Chapter 1ON THE SOUL

     In the name of Allah, the Merciful, the All-Merciful.
     Allah alone helps and directs to the right course.

Bodies are either natural or artificial.  Artificial bodies, for example, chair and couch, exist as the result of voluntary action only.  Natural bodies, for example, stone, palm-tree, and horse, all come to be and pass away. Aristotle has explained in his works about the things which are common to natural things (i.e. about the general principles of physics) that all these are composed of form and matter just like artificial bodies, and that the condensation of gold has the same relation to pure gold, its matter, as the form of the couch to wood.
 Matter, as explained in the first book of Aristotle's Physics (Fol. 139A), is either formless by itself, and what is generated from it is a simple body (i.e. an element); and the simple bodies (i.e. the elements), as explained in other places, are four, namely earth, water, air and fire; or matter has a form.  With the exception of the four elements matter of this description can only become the matter for any natural body if another element is mixed with it.  For when a simple being (i.e. element) changes, it changes either in its form, and thus another simple being (i.e. element), opposite to it, is generated from it--from water, for example, is generated air and earth--or it can change in its accidental qualities, but this is transformation, not generation.  Now, when an element is bent upon producing a compound, it has necessarily to be mixed with more than one.  Similarly, some artificial bodies originate from one existent formed thing, since the species of art are accidental qualities of natural bodies, although their substratum receives them from the artisan only.  Some artificial bodies receive the accidental qualities by means that all come from art exclusively, for example, the chair; for its wood receives form through art, and the instruments by which it is made are products of art as well.  But there are other artificial bodies in the case of which the first mover is art, while the instruments are natural bodies, as for example, glass which is only finished through the heat of fire, fire being a natural body.  This latter kind can be sub-divided:  either all the instruments are things which do not exist as a result of voluntary action, or the instruments are in part natural, in part artificial.  But how do those things that have natural instruments become artificial?
 I answer:  The mover is either accidental or essential, for it may set in motion by itself, or it may set in motion through the intermediary of one or more other things, and these intermediaries are instruments or quasi-instruments for the mover.  But the art does not set in motion by itself, but sets motion through instruments.  That which is set in motion in such a way through a mover has more than one mover and will
 have a last mover and this is the one that is in contact with the thing moved, for example, the axe with the wood, and this is the mover from whom the art derives or who is the art itself.  And as has been shown, the last mover cannot set in motion without the first, whereas the first can set in motion without the last, for the motion comes to be at the precise time when the first mover originates movement.  Hence, the first mover is the agent for the motion and to him it is ascribed, as has been shown in Physics VIII.
 

Everything moved in which the first mover is nature is natural, and everything in which the first mover is art is artificial, whatever be its instruments.
 As for the fact that the art may change, this is due to an accident or second intention, this has been explained in Physic II.  ( Fol. 139-B ) Forms, of whatever shape they are, are either natural or artificial.  The forms are, in short, the perfection’s of the bodies in which they are.  They are not mere perfection’s, but perfection firmly established in the bodies like permanent acquisitions.  When perfection reaches this state it is called an "entelechy."  Forms are then the entelechies of bodies that possess entelechies potentially.  These entelechies are of different kinds:  those that perform their actions in the things to which they belong without being moved essentially, and those that perform their actions while being acted upon.
 Since everything moved as a mover, the entelechies are moved either by a mover outside them, like most of the artificial bodies, or by a mover inside themselves.  In art this is like the automatic machines that are set in motion to perform their actions that remain in them for some time.  I have summarized this in the science of Politics.
 

As to natural bodies, they have their mover inside the whole body, and the natural body is composed of mover and moved.  Artificial bodies have their mover outside the thing moved, and the thing moved is connected with the mover by accident.  Natural bodies are, however, not like this.  As to the question whether there is in nature anything similar to art, this demands an inquiry, although if there is, this resemblance would seem to be of a different kind. Natural bodies move to their natural places only when they are in places not natural to them, for, then there exists in them a capacity according to nature and therefore they have their movements to their places.  They only change their directions by accident.  For their not being in their natural places is only due to an obstacle that prevents them, but when the obstacle is removed, they move to their natural places.  Hence, it has been assumed that the mover in natural bodies is the same as the moved.  But this is not so.  For in so far as the stone is in potentially is below and moves in as much as it has weight, the thing moved in it is its potentiality of moving downwards, and the mover is the weight.  hence, it moves with one kind of movement that is natural for it.
 

There is nothing in the thing moved in opposition to the mover, for the thing moved is only its potentiality.  This is not the case with those bodies that possess souls.  For the thing moved possesses a form for the sake of which it performs a certain action, and either the mover moves them in opposition to their natural action, or moves them according to their nature, e.g. raising the hand and jumping, for though it the body is moved and this is a motion upwards, and therefore the soul moves through an instrument, i.e. the natural warmth or something like it.

 Forms are of two kinds: (I) the entelechy of a natural body in which the mover and the thing moved are not joined essentially.  It is moved without an instrument but is moved as a whole.  The other (ii), the entelechy of a natural body moved through instruments.  The first is called nature par excellence the second is called soul.
 Soul is then the entelechy of a natural organic body.  There (Fol. 104A) is a first and last entelechy.  For a geometer, when actually geometrizing, is called geometer according to the last perfection.  So when he geometrizes he is in his last perfection.  But soul is the first entelechy.  Hence, soul is a first entelechy in a natural body.  And, the existence of a body with soul is life, so every body having a soul is alive.

 It is clear that soul is an equivocal word.  For our expression "entelechy" is said in an ambiguous sense, similarly our expression "body" and "instrument."  Soul then is said in similar ambiguous sense as "weak", "many" and the like.  hence, it is necessary to specify it and so it is said:  the nutritive soul is the entelechy of the nutrient organic body, the sensitive the entelechy of the sensitive organic body, the imaginative the entelechy of the imaginative organic body.  Soul is, however, predicated of the reasoning soul in a sense though equivocal but more manifest than all these.  All knowledge, as Aristotle says, is noble and beautiful.  But some knowledge is nobler than others, and I have already enumerated the grades of sciences in their nobility in many places.  The knowledge of the soul (i.e. psychology) precedes all sciences, physical and mathematical, with all the kinds of dignity.  Again, every science depends upon the science of the soul, because we cannot apprehend the principles of other sciences unless we apprehend soul an know what it is by its definition, as shown in other places.  Again, it is a generally admitted fact that one who is trusted in his knowledge of the state of his own soul is even less fit to be trusted in his knowledge of others.  If then we do not know the state and the nature of our soul and if it has not become clear to us whether what has been said about it, has been said correctly or cannot be relied upon, we are even less fit to rely on what appears to us in all other things.

 The knowledge of the soul precedes all sciences also because, it gives the inquirer a capacity to grasp those premises without which the physical science cannot be complete.  Moreover, political science cannot be treated in an orderly fashion before one knows the nature of the soul.  Again, a science is ennobled either by certainty, that is, when its statements are precise and explicit, or by the nobility and fascination of its subject-matter, as it is the case with the science of the movement of stars (i.e. Astronomy).  Now, psychology fulfills both conditions.  Psychology is worthy of being the most noble science with the exception of the science of the First Principle (i.e. Metaphysics).  It appears that Metaphysics is different, in an other way< from all other sciences, just different, in an other way, from all other sciences, just as the existents are different from the First Principle.  Again, the knowledge of the First Principle is impossible except when it is preceded by the knowledge of the soul and the intellect, otherwise it would be imperfectly known.
 

The most perfect method of knowing the First Principle is the science in which the capacity provided by psychology is used.  Knowledge of a thing has several kinds of relation; the first and the most deserving of priority is the knowledge of what it is; the second, the knowledge of its particular essential qualities; and the third (Fol. 104B), the knowledge of its general essential qualities, is knowing only in metaphorical sense. The knowledge of the quiddity of a thing is either imperfect, i.e. known through only one of the complete parts of its definition -- this is of various kinds, and the explanation of its kinds has been given elsewhere -- or it is perfect, i.e. known through what its definition indicates.
 

Definition per prius et posterius is said of meanings all of which are equivocal in their existence and are equally predicated of an object; definition, therefore, indicates a particular quality of the thing.  The expression per posterius is used because of the posterity of everything that is composed of elements which do not constitute the thing, it has been explained elsewhere that the things which constitute a thing are its causes.  The definition per posterius are not composed of causes, but are only composed of qualities, either far or near, essential or not essential.  The definition per prius is that which is composed of causes, and this has also many genera, some of which are composed of farther, some of nearer causes.  This (i.e. the definition per prius) is a definition in a stricter sense.
 

Causes, in short, are four, matter, agent (i.e. efficient cause), form, and end (i.e. final cause).  They are sometimes particular, sometimes general, that is although specified in form yet general.  The most apt to become a definition per prius is a definition that consists of the particular cause.  Similarly, the causes are sometimes potential and sometimes actual; and the most apt for the definition per prius is then the one that consists of the actual particular cause.  This type of definition is either self-evident and thus axiomatic, or derived and found out either by division or by composition, as shown elsewhere.  Definitions like these are in the same category as axiomatic definitions, or they are found out by absolute demonstrations, and this is three ways:  (I) as the conclusion of a demonstration, (ii) as the principle of a demonstration, or (iii) a demonstration with a different arrangement of the terms.  This is the most perfect definition and the most deserving of priority.
 Signs provide the parts of the definition by accident, not essentially.  All this is summarized in the Posterior Analytic’s. Since we are trying to investigate this kind of knowledge concerning the soul (i.e. its definition), how natural it is that its attainment is difficult, but although difficult not impossible.
 

It is clear that the definition of the soul is not an axiomatic definition, but a derived one.
 Again, among the kinds of knowledge that follow, in the first instance, if the knowledge of  what the thing is and they are as it were a supplementation of this, which is to know whether the thing is one or not one.  If one, whether it consists of parts or not, if it does not consist or parts whether it has several faculties or only one faculty -- all these needs investigation in psychology.  For all these are views of those who proceeded (Aristotle).  For some of those who proceeded him believed that "soul" indicates plurality, as analogous words do.  Others, like Democritus and those who believed in atoms (Fol. 141A), held that it had many parts separately.  yet others like Galen, the physician, held that the soul is one but has many parts in its substrata.  This is a view which Plato had already recorded in the Timaeus.

 A similar question is asked about "soul" in particular, and its solution is so much desired at the very start that it would seem that psychology is only studied for its sake.  Namely, the question whether the soul is separable or not at all separable.  Hence, you find that Aristotle says at the very beginning of Book One that, if there exists a particular action of the soul which distinguishes it form the body, it may be separable.  He starts with this topic before beginning the main investigation, because of the aforementioned desire.  All this adds to the difficulty of this part of natural science.  Since we are determined on this question, we have to ask whether it belongs to the study of the bodies in which the soul is, or whether it belongs to the qualities which are ascribed to the body in which soul is, like health and illness, or to the actions which are ascribed to the soul, e.g. anger and contentment.  Now, if the soul is not separable at all, all the actions related tot he soul are shared by the body, although some exist because of the soul and some because of or through the body.
 

As has been shown in the Posterior Analytic, no definition can be formed unless the genus by which it is described is found, for, when we frame a definition which is not composed of the genus of the thing, its parts are indicated by derived words.  For all the things that can be predicated of a thing only the genus can be indicated by primary symbol (i.e. non-derived word); this definition would express the existence of a thing in a substratum by which it is not explained, so that it would be incomplete and would indicate an imperfection.  Hence, we have first to investigate the genus which is to be predicated of the soul and by which it is described, in order to find a way to define the soul.  Now, genus and differentia have different aspects, for, the genus is potentially the differentia by receiving its form through the differentia.  So potentially it resembles, in a way, the potency which is predicated in matter.  Hence, potentially, genus is a thing extraneous to it (i.e. the differentia).  Now, the differentia is potentially the definition, just as the whole is said to contain potentially its parts, and the genus exists within the differentia potentially in a manner analogous to the existence of the parts in the whole.  This is because when each -- genus and differentia is taken as designating the concrete whole, then the one is genus in so far as it is genus and the other is differentia in so far as it is differentia; but when they are taken in so far as they are definitions, then the genus is the conclusion of demonstration and the differentia the principle of a demonstration or they both are something analogous.  And, therefore, in so far as they are parts of the thing defined, each of them is then potentially the definition but in a different was, as stated (Fol. 141B) in the Metaphysics.
 

Since, as explained in the Posterior Analytic, there are three methods for the derivation of the definition:  (I) the method of division, (ii) the method of composition, and (iii) the method in which syllogism is employed, we must ask which method must be followed to define the soul.  For this method of division will not do, for the genus under which soul is subsumed us unknown, and if it were self-evident the question whether it is a body or not would not arise.
 Nor can we follow the method in which syllogism is employed, for the representations in which the soul presents itself are one, and some of them are composed of things which do not belong essentially together, nor are they necessary deductions from syllogisms, so that it would be possible for us to consider and use the most strong of them.  In short, there is no way for us to establish a priority of some to others.  Again, when we observe the classes in which the ancient philosophers divided these representations, we will find them neither contradicting nor consistent, but would seem clear to him who observes then that term soul is predicated equivocally.  Now, if it is possible to understand the representations of the soul, and we are asked for a proof that this is so, if there were any proof, then indeed we find only one among many definitions of which the soul is predicated, nut not the real notions of which soul is predicated.  For, if soul is predicated equivocally, it is certainly predicated in an ambiguous way.  Therefore, only the method of composition remains.

 Now, it is evident that the method of composition can only be used for something whose existence is previously known, and the soul is one of the things whose existence is evident; and ask for an explanation of its existence is like asking for a proof for the existence of nature.  Such a question can only be asked by someone who does not know the difference between self-evident knowledge and the knowledge through something else.  Since some know things are self-evident, e.g. "horse and man possess soul," but this type of thought can only become coherent through considering all that of which soul is predicated, he (Aristotle), therefore, studies the souls of all the animals; for, about the forms of plants, there is still scope for investigation.

 Now, this kind of study was never undertaken by those who preceded Aristotle.  The only aim of the previous philosophers was to consider the human soul in particular to the extent that was necessary for their studying political affairs to which their investigation was at that time, confined, whereas the various kinds of souls are studied not only for this purpose alone, but because the science of every soul is a part of natural science.

 We, therefore, say:  every species of animal is a body composed of parts unlike to each other and not connected, but its parts are separate according to their particular ends, and meet together either by coalescence or at a joint; and this takes place when one of the two is set in motion by the other, for, it is common to all animals.  Again, it is (Fol. 142A) a well-known fact that every animal is capable of motion, possesses senses:  it perceives through parts that move and perceive.  It is, therefore, composed of the two (i.e. movement and perception).
 It is evident that the animal is a genus of body and form, but as to the question in what respect it is said to be composed of body and form, and whether the soul is body or form, this becomes clear to him who relies on the study of his own soul.  In his book on the soul, Alexander has discussed about this clearly, so it may be learnt from here.

 It is, therefore, established that the soul, as shown before, is a form of the like of this body; and when we use the method of division which we have summarized this implication must be accepted -- namely, that the soul is the entelechy of a natural organic body -- since it includes every soul and everyone of its faculties, no matter whether it possesses certain particular faculties or certain others.  Since our word "entelechy" is said ambiguously and our expression "natural organic" is not a synonym, like our expression about a dog as "barking dog", it is clear that soul is said in an ambiguous sense, and that it is an equivocal term.
 It is also clear that there is no one nature which comprises all souls, for if the soul were homogeneous, its actions would certainly be homogeneous, whereas no two actions of an animal, like nutrition, sense-perception, locomotion, imagination and reasoning, are homogeneous so that the corresponding faculties of all these actions, too, are not homogeneous; but some actions precede others, e.g. nutrition and sense-perception, and some are similar to each other, e.g. sense-perception and imagination.  Similarly, the faculties and the soul are in a  relation of priority, posterity and symmetry.  hence, it is impossible to include in the definition of the soul all that is called soul in one and the same way; hence, the method of demonstration cannot be used in the case of the definition of the soul.
 

Neglect of this study is one of the reasons due to which the right treatment of soul escaped the philosophers previous to Aristotle.  For they all agreed that soul is a substance, and, therefore, they wanted to subsume it under the species of substance, some saying it is fire, and others blood or air.  And, yet another who realized the absurdity of its being a body made efforts to subsume it under another category.  In short, all of them gave it a place in the ten categories.

 Since, it had become clear to Plato that the soul must be subsumed under substance which is, as explained by him, predicated of the matter which is body, and of the form, and that it is absurd to assume soul as a body, he made efforts to define soul in a way to specialize to it.  And, as he postulated, he investigated that which is shared by all of them, and found that sense-perception is the characteristic of the animal, and motion is common to all, he, therefore, defined soul by saying:  "It is a thing which moves itself."  For the word "thing" indicates here the same as we say "being."  Such was his definition of the soul, because Plato believed that every mover is moved, since according to him (Fol. 142B) nothing can cause motion unless it is moved; and this view has been summarized in Physics VII.

 Concerning the refutation of the views recorded about the soul, Aristotle has explained it thoroughly in the first book of the De Anima, so let us assume his conception in general.
 Let us now turn to the study of the soul which Aristotle believed initiates out in the way we shall describe.  Since some souls are per prius by nature, and some are per posterius, and the last of all in appearance is the imaginative soul.  For the sense-perception precedes them.  It is sometimes assumed that some animals have no imagination, e.g. the worm and the fly, and if they did possess imagination, it is neither separable from sensation nor is it determinate.
 The most prior of all faculties of sensation is the faculty of touch, the faculty of sense-perception being preceded by the faculty of nutrition which is, hence, the most prior of all the faculties of soul.
 

The reasoning faculty, though itself soul, is the last to appear in nature in the same way as the perfect comes after the imperfect in nature.  Aristotle has, therefore, started with the investigation of the nutritive soul.  This kind of the soul has two faculties:  (I) one the faculty of growth, and (ii) the other the faculty of generation.  The nutritive faculty, thus, precedes all and is, then, the most prior of the faculties of soul.
 
 
Chapter II

 We say:  The opposite of being is not-being.  Not-being is either impossible, i.e. that which cannot exist, or possible.  What is possible is of two kinds:  one, the necessary, is that whose non-existence is impossible, and the other, that which just exists, i.e. that which exists at a particular time; so it is clear that that which just exists was non-existing at another particular time.  It is sometimes assumed that it entails for its non-existence in an infinite time.  But if this is the case, it is not so by accident, as has been summarized, in Physics VIII.  As has been shown there, let it be understood that the non-existence of this is also absolute non-existence.  But the absolute non-existence necessarily implies possibility, since necessarily it is a equivocal term.  The relation of non-existence to possibility is clear from what we have explained in Physics I.  Not being is the opposite being in relation to matter in so far as it is essentially an opposite being.  By opposite I mean that of which the two contraries, the affirmative and the negative, are composed, i.e. whenever the opposite I mean that of which the two contraries, the affirmative and the negative, are composed, i.e. whenever the opposite is predicated of one and the same substratum -- I mean one thing and its contrary the two statements become contraries, and are distinguished according to being true or false.

When, for instance, we say about Zaid, when he is ill, that he can never recover or not, the opposite of "he can recover," which makes up this statement, is not the existence of privation of health which is linked up with its possibility, but it contains "the privation of health" at the moment which contains the statement, "he can never recover," no matter whether this time is determined or not determined.  Hence, the relation of "health" to the substratum -- in respect of that which has a like, like this opposite -- is the possibility of health.  The potentiality, in the relation of health to matter is the non-existence of health, but not in so far as it has an opposite in potentiality.  It is the relation of the opposite form to the substratum, but not in so far as it is opposite.  Therefore they are mutually interdependent.
 The possible and what is potential are one in the substratum on two in expression.  hence, as shown in Physics VIII, it necessarily follows that potentially precedes actuality in time, e.g. it is said of the moon, "it can eclipse and it is potentially eclipsable", but in an equivocal sense; potentiality in the moon is nearer to the univocal expression than our expression "possible," because "possible" is equivocally used for both "the moon" and the "ill man," and therefore, "eclipse" has been enumerated among the necessary things.

 As explained in many places, potentiality precedes actuality, and actuality is divided into ten categories.  No potential, however, does become actual before it reaches a state when change becomes necessary, as has been shown in Physics VIII. Change takes place in substance, quantity, quality and space, and it is the faculties of these four through which the thing moved is set in motion.  The faculties by which the thing moved is set in motion are called passive and changing faculties, the faculties connected with this process being changing faculties.
 

There is hardly any category among the remaining categories that is being acted upon, since the entelechy of their passive faculties is not change, but it is due to change, and hence, it takes place at the present time.  This relation, however, is not found in the definition of the three categories.  Quantity, for example, is not defined through the relation of the substance, i.e. the substratum, to it, nor is quantity.  But quantity is the most apt for this, so much so that it has been assumed that it can be separated from substratum.  All the other six categories are defined through their relation to a substratum.  But the categories of Position and Possession have substance in their definitions, whereas the remaining four are different, since their substrata can be something different from substance.  All these, however, have this in common that they have substrata, in the definitions of which this relation is not found.
 But the categories in which the relation is found in the definition of one of the two substrata, in so far as they are two contradictories, are Position, Possession, Space, Time and Passivity.  Those categories in which the relation is not found in the definition of one of them, are of two kinds:  either both of the substrata are together in actuality, and this is the category of Relation, or one of the two is actual and the other potential in so far as it is potential, and this is the category of "Being acted upon."

 The problem whether there exist two existents in actuality that are substrata for a relationship which is found in the definition of the two and is due to Relation, has been explained elsewhere.  Now, it is obvious that that which acts, in so far as it is that which acts, exists in actuality, and that which is acted upon exists in potentiality, since from our word Yafa'l (it acts) it follows essentially and not accidentally that it exists in actuality as a fully specified particular, and from mayanfa'al (that which is acted upon) it necessarily follows that it exists in potentiality.  That which acts accompanies in existence that which is acted upon, and it necessarily follows that it exists in potentiality.  That which acts accompanies in existence that which is acted upon, and it entails that its being is necessary.
 

The thing moved has either eternal or transitory movement.  The mover of the eternal movement is one and is moving eternally.  hence, the mover of the eternal movement is always one, existent in actuality, and he is not such as to move at one time and not at another.  That which causes a transitory movement is either one and the same which is at one time moving and at another not, e.g. the weight in the stone that moves at one time and does not move at another, or is one after another.  Whatever the case, this kind of mover.  It, therefore, entails, on both (whether the mover is one or more than one) that at a certain time they do not move, the more explicit being the former case, i.e. the mover being one that moves at a time and does not move at another, as the weight that is hindered by an obstacle, similarly, the souls of the animals prevented from movement, the plant that has not yet started growing, the fire when it finds nothing to cool down.  All these, then, do not move, but are capable of moving.  As has been shown, that which is possible is potential, and that which can move when it does not actually move is potentiality, and this potentiality characteristics the active and the moving faculties.  Thus it has been shown what the moving faculties are.

 Those faculties that are moved are necessarily in a body, because everything that is moved is divisible, and they are called faculties per prius.  But the moving faculties are only called faculties per posterius and relatively.  It has been shown and summarized in the Metaphysics how the moving faculties exist sometimes in bodies either as forms or as accidents, and sometimes do not exist in bodies so their existence can be shown.  As such are enumerated the Active Intellect and the Acquired Intellect.
 

But the souls of the spherical bodies are not at all and by no means faculties.  If they are called faculties it is so in another way; and in relation to the Active Intellect, they are moving faculties, but not is so far as the Active Intellect resembles them but in so far as they resemble the Active Intellect in existence; and so they are called faculties by way of accidental resemblance.  This is a different kind which is called so ambiguously, but this is the ambiguous meaning nearest to the equivocal sense.  Food can be understood as potential, just as "meat" for the wild animal.  Food can also be understood of the last food as for example the blood (into which the digested food turns).  The faculty of nutrition, then, is a faculty by which the body becomes "moved" being, therefore, a passive faculty.
 As everything which changes has a changer, the potential food which is the far food has necessarily a mover that turns it into actual food -- its activity being to provide nourishment.  The mover is the nutrient, and the body that has a faculty like this is that which is nourished.  The forms of the words correspond to the meanings they indicate, since the nutriment is that which is being acted upon, while the perfection of the mover is that it is moving, and the form of its verbal expression is the form of the expression "movement."  But why this is so, we shall explain somewhere else.
 

What takes food is either a plant or an animal, in both of them there is a moving faculty; so the body which takes food has a moving faculty.  Every moving faculty is necessarily a perfection. Hence, in the body there is something that exists actually and by which the food is moved.  As it is clear from the investigation about this faculty (i.e. the faculty of nutriment), the process of nutrition takes place only through organs.  The nutritive faculty then is a soul.  Sometimes they doubt about Quantity whether its faculty is a soul or not.  If its faculty be a soul, then every soul does not necessarily move by an organ, because Quantity consists of parts alike each other in sense-perception; even though there is no growth in Quantity by addition to that which is already there, as in the case of the stone.  Similarly, objection is raised about the sponge of the sea as to whether it is an animal or a plant.  In short, we find that Nature does not change from one genus into a more perfect genus unless it produces an intermediary; but the investigation of this is somewhere else.
 

As we have said, change occurs in substance and occurs in the rest of the categories.  Nourishment takes place only through producing a movement in the substance.  This is clear when we investigate food.  For blood and milk are different from meat, and different from the water mixed with earth which is the food of the plant, as has been described in the book of Animals and the book of Plants.  The movement of food is transitory, food being generated and the nutrient generating.  Hence, the function of the nutritive faculty is to produce movement in substance.  We have thus found the genus under which the nutritive soul is to be subsumed.  This faculty is an agent (active), and every agent is actually existing; and every being that has no other activity has two perfection’s:  a first perfection which is its existence in potentiality, and a last perfection which is its existence in motion.  Now, the nutritive soul is the first entelechy of the nourished.  But as to the nature of its generation -- and, this is the definition which is called the Principle of Demonstration -- this will be clear from what I say:
 

Food is either potential, or actual, and that which is potential is either far, as the elements, or near, as meat and vegetables for the animal, while the near nutriment for the plant has no name.  The far is that in which the mover is not the nutritive faculty, and the near is that what is moved by the nutritive faculty.  This latter (i.e. the near one) has aging grades:  (i) the food that reaches the organs of nourishment in the animal, and the moisture that exists in the roots of the plant, (ii) the food that is nearer than these, for example, the blood that runs in veins and the milk (i.e. sao) in the plant as long as it is tender, and (iii) the last perfection, for example, the blood that turns into flesh, and the sap that changes into fiber and so it is acquired by the fiber.

 And as everything that is opposite to that what is potential is opposite to that what is actual, we say:  He who holds that food is derived from Al'khaz (that which nourishes) does not contradict the view of the one who holds that all food is from the like.  For the first proceeds from that which is food potentially and the second from that which is food potentially and the second from that which is food actually, and food is said of both equivocally -- this rejects the doubt that arises concerning food.  As to which particular species of generation produces food and how it generates, all these will be made clear by what we say:
 We say:  Every being that comes to be and passes away has an activity peculiar to it and for the sake of which it comes to be, as has been shown somewhere else.  And, through this particular activity it has become a part of the universe, because nature has done nothing in vain.
 

As every generation has a generator, the generator either belongs to the species of the one that comes into being or to its genus.  The thing generated is either artificial -- its generator then being art, but art is in various matters -- or natural, the generator of the natural product being natural.  In short, the thing moved sometimes belongs to the species of the mover and sometimes not; for fire comes from fire, heat from heat, but hard is caused either by cold or by hot.

 Hence, the faculties of the physical bodies are either movers or not so.  The moving faculty then performs essentially and primarily those actions which belong to their species, and secondarily and accidentally something else and that according to the matters in which they act.  every moving faculty, besides the fact that it has its peculiar kind of existence, has an "intention" by which it produces its like.  Among the elements this potentiality is evident in fire, next is air, and the least evident is water and earth.  But like of this potentiality only imparts natural forms tot he bodies having parts alike to each other.  But fire is sometimes produced by striking the fire-stone.
 

All animate bodies have a generative faculty, which, in short, is the faculty which generates from the food potentially a body which is similar to the body in which it is.  So necessarily this animate body, in the peculiar existence of the faculty, becomes an "intention" by which the faculty moves towards the existence that characterizes it.  This generative faculty is both ruling in that body, being in a part of the faculty which is the principle of that body, as for example, the heart in the animal, and a serving and particular being in every organ of the body.  The form of the bone in the body, for example, is a potentiality that stirs the food, which is a bone potentially, to become an actual bone.  The case is similar with regard to flesh and the rest.  That which is in the 'beginning' comes into being from the food that is in the being.  This has been summarized elsewhere.

 It is clear that a body that has such a form is composed of the elements, and that it is composed of earth and water.  As shown before, the composed is mixed primarily only when its ingredients are moved in space.  Then they come near to each other, and next each part is transformed into another in the way shown in the first book of De Generatione et Corruptione. But this (i.e. transformation) is not possible through cold and is possible only through heat.  This heat is the organ of the soul and is called the innate animate heat, as has been explained in the seventeenth section of the book of Animals. The innate heat is, therefore, the organ of this soul.  Then, the nutritive soul first moves the innate heat, which is moved by itself, and moves through innate heat the food.  For that which is not moved cannot move what is not in it except by moving it first through a body that is in it, sa has been shown in Physics VIII.
 

This faculty (i.e. the nutritive faculty) causes a movement like this, and changes what is potentially an "intention" in it to be actually like it.  Since all that contains moisture is speedily acted upon and dissolved, the body of everything which has soul is like it.  And, hence, if it is bent upon to preserve that body, it must possess a faculty like this, because if a body is left without a substitute for that portion of it which is dissolved, the body is sure to perish.
 

All natural body has a particular kind of size by which its being is completed, as it is evident in many plants and animals.  it is not provided with that size from the very beginning of its generation, since then the body did not yet possess a faculty through which it could be moved to that kind of size.  This faculty is the soul of growth. Hence, the nutritive soul prepares more food than what is dissolved so that it does not only become a substitute in the part of the body for what is dissolved but also a surplus, and then that body is moved and gains a kind of size which it did not possess before.

 This "movement" evidently has no name which comprehends it as well as the name of the movement of growth and the name of the movement if increase, and their two opposites, the movement of decay and diminishing.  I have explained this "movement" in the first of De Generatione et Corruptione.  Now, this is another faculty which is in the first nutritive faculty like the form, the first faculty being for it like matter, because the faculty of growth cannot dispense with the nutritive faculty, and hence, when the body reaches its natural perfection, the nutritive faculty produces less food, but in a quantity sufficient to substitute what is dissolved from the body.  This is the function of these two kinds of soul.
 Every body that takes nourishment is either reproductive of not reproductive.  The reproductive body, n short, is that body whose form possesses a faculty which moves what belongs in potentiality to that species and turns it into that species in actuality.
 The difference between this reproductive faculty and the nutritive faculty is this:  the nutritive faculty turns each of those parts which potentially exist, actually into its parts, while the reproductive faculty turns what is potentially that species into a body of that species without employing the parts of the nutritive faculty in it, as has been explained in the sixteenth book of the book of Animals.
 

This reproductive faculty is related to the body reproduced just as the art is related to the chair, because the reproductive faculty, as explained in that book, is in a matter different from that of the reproduced in the same way as it happens in the art.  This faculty (i.e. the reproductive) is not in a body but it is mind in actuality, as has been shown in that book.  But the nutritive faculty is a faculty in a body, since it is material.  Hence, when the reproductive faculty acts upon matter suitable for it and makes it generate the same species in it, that form (i.e. the reproductive) causes this kind of movement (i.e. reproduction).  Thus it is clear that the action of the generative faculty is not through the nutritive faculty, but is something else.
 

It is also clear that the faculty we described as reproductive of the species does not reproduce something like itself in the same way as we say of a substratum that it is like the art.  As shown before, this faculty is always found connected with a certain body in order to move that which it has to move, namely, that which is potentially moveable.  The body whose form is like this is sometimes found in air and in water, and the generation of such beings is caused by different movers, e.g. the putridity in animals out of which they are generated.  These are bodies that are not reproductive but they are provided with nothing more than their mere existence.  their species, therefore, needs another species for the preservation of its existence.  But the species of the animate and reproductive bodies are provided besides their existence with a capacity that provides them with a co-nature of continuation, and since it has a connection it is a being.  This is the most imperfect stage of the necessary existence.
 But the continuation of the species that are not reproductive is the arrangement of the periods of their existence.  The reproductive species then is in the middle between the noblest rank of existence, namely, the absolutely necessary existence, and the lowest rank of existence in which the meaning of necessary existence is "arrangement."

 Since material bodies have no necessary existence, they have been given reproduction in exchange for it.  Reproduction takes place through a faculty by which it moves the food until some of it becomes a body that has a faculty like this, I mean the faculty of reproduction, and it has already been said what the nature of this body is.  It is called sperm in those animals that have sperm, as has been demonstrated in the book of Animals. This faculty (of reproduction) is like the form for that (i.e. the faculty of growth), and as though it were the extreme of the movement of the faculty of growth, and hence, it acts only when it reaches the perfection of its movement.  The nutritive faculty is like matter for the reproduction faculty and the faculty of growth is like immediate antecedent.  And this (i.e. the reproductive faculty) is like the end; and we do not find for the nutritive soul any faculty more perfect than this.
 

It is clear that the nutritive faculty always produces in such bodies more nutrition than is required for the preservation of the body, and that this surplus is first spent in growth, and when the body is mature, sperm developed from it.  As the sperm is the surplus of the last food, hence, the faculty of reproduction does not cease except in old age, when the nutritive faculty restricts its activity to the preservation of the body only, the nutritive faculty is then singled out from the growing faculty and exists exclusively alone.

 Hence, it has been shown what the nutritive soul is, why it is and which are its organs; and that the soul and all its faculties are in one substratum, no matter whether it is single part or a part that comes to be in succession in it, as we find in many plants and in some animals.
 
 

                 Chapter III

 Every body, as shown elsewhere, is composed of form and matter, both being incorporeal while the body exists through both of them.  Matter, in so far as it is matter, does not essentially possess a form, but it receives form.  In a body form does not actually separated from matter, nor matter in it actually separated from matter, nor matter in it actually separated from form.  But in a body composed of the two each can be potentially separated from the other.  This is evident in the transitory bodies. But, body, matter and form are predicated of the spherical bodies that come to be and pass away equivocally, as has been shown elsewhere.  As shown in Physics I, an organic matter is sometimes separated from form, as becomes manifest at the moment of decay.  it is thus clear that the fully specified particular is neither actually distinct nor changeable in any way of change.  Change only occurs when the fully specified particular is moved to come into existence or to cease to be.
 Matter does not at all exist separately from form, but it is separated only to be connected with another form; and then the absence of form is manifest in it.  It necessarily follows from this that the form by itself is also separable from matter either to be connected with another matter or to have existence by itself, since, otherwise, it is not possible that matter is somehow different from form and form from matter, and change would be meaningless, and there would necessarily follow from it other absurdities, e.g. generation and corruption, and "motion", in general, will be meaningless; to assume the existence of a mover belonging to the species of the thing moved, will also be absurd.  Again, just as the matter of water, when it disappears and turns into vapor, exists in connection with the form of caper, not so that the form of vapor is continuously connected with the matter of water.  Form then has either matter, not so that it is a matter for the form through which the form becomes a form -- just as matter is represented by the form, when it is that particular specified body -- but so that it exists by nature it is in a substratum without having any possibility of existence in itself, since it is an "imattered" form; or form possesses matter in a way suitable to the existence of matter with form.  For whenever matter receives form it becomes the substratum for the form, being in itself formless matter.  hence, there are in matter forms which are potentially opposed to each other.  So, this potentiality is a necessary corollary of the matter and is not separable from it.
 

Hence, if it is possible that a form exists which has no opposite, for the matter with which the form is connected is only a substratum, it is matter only in an equivocal sense of the term, since matter has essentially no relation with any particular form; but all forms are related to it equally.  this is because everything moved has a mover, for example, the pieces of woods in art which are not all without form; and when whichever particular form is determined in matter it remains all the while capable of receiving the contrary form. When the form comes to it, it sets it into motion.

 A mover is of two kinds:  either not-homogeneous as the mover of the spherical bodies which moves them by necessity, or homogeneous.  This second mover, then, has matter which is again capable of receiving a form opposite to the first.  Let AB, for example, be water.  Now, in AB there is the form of the water, and let that be coolness, since it contains coolness in actuality which is air in potentiality.  So, let there be H for the potentiality of air.  Now, in AB there are B and H.  Hence, AB causes motion in so for as it is B, and suffers motion in so far as it is H.  That which opposes (i.e. the opposite form supposed to be received by matter in potentiality) is A which has J, then in AJ there is J which is its form and it contains M, that is its being that which is potential; and what is potential cannot be moved without a mover.  The bodies of AB and AJ, therefore, are at rest in so far as they are H and M, and movers in so far as they are B and J.  hence, the capacity of H is necessarily moved by J, and the capacity of M by B.  If B is equal to J then it will not be moved, nor with either of the two.  If on the contrary, one of the two is stronger, and let B, for instance, necessarily, move AM, the matter being B and its substratum, then, there will necessarily follow H, because BJ are homogeneous and contraries.  But this is not the case with that in which forms are not contraries.  For example, "This thing is wood, and a chair potentially."  Now the thing may be a chair while it is wood as it was so before, because the chair is not homogeneous to the wood in the same sense as "hot" is to "cold," nor does the existence of the potentiality of the chair in the wood essentially belong to the wood, nor is the wood the cause of the existence of the potentiality in the wood except in a different way.

 As concerning "hot" and "the potentiality of cold," the fact that it is hot is the cause of its being potentially cold, and therefore "hot" is potentially "cold" since "hot" and "cold" are related to matter in the same way.  hence, matter receives "hot", in the way as it receives "cold", these two being different from each other.  If matter were to receive the two together, then surely there would remain no difference at all.  they are different from each other only because matter belonging to both of them accepts "straightness", and the "straight" is the first cause of contrariety, since the "straight" brings about perfection, but it is not perfect in itself.  It has, therefore, a middle and two extremes, because it is continuos, and everything that is "continuos" consists of parts -- but this discourse is suitable for the study of the cause of the existence of contraries -- and the faculty that is moved and belongs to it (i.e. the continuous) has nothing to make it "more" or "less" except that it is in a larger or smaller body.  A body is larger or smaller in so far as it is actually that specific body, because it is due to it quiddity that the existing size belongs to it by nature.  "The less" and "the more" exist for two contraries only in so far as they actually exist.  Moreover, "the more" and "the less" are called by the way of analogy.  hence, it follows necessarily, when the matter of the contraries is one, that one acts and the other is acted upon.  But when the matter is not one, then neither of the two is acted upon by the other, but the moved is set into motion and the mover causes motion.

 Matter is either near or far.  Now, the contraries whose near matter is one in species are like air and water; but those whose far matter is one in species and whose near matter varies in species are like the artisan and the wood in the case of the chair; and hence, no artisan can be greater than the other in the case of the one and the same wood.  Since the far matter is common to mover and moved, sometimes the wood moves the artisan as e.g. the fatigue that overtakes him, and in this case the matter is far.  For everything that sets something into motion, while matter of the mover and the moved is different, not at all common, does not procure fatigue to the mover, but since the mover possesses matter, it follows necessarily that the mover has a relation with the moved.  This is the case, for example, with the spherical bodies and the elements.  But if the mover has no matter, then that mover moves without fatigue, and without any relation in quantity to the thing moved, because it has no parts.  And if the mover is not sufficient by itself, then its movement will have a relation to the one that assists him.  If it is possible, the mover moves sometimes and does not move some other time, like "intellect", or it causes different movement, as it happens in most intermediate things.

 If the mover is sufficient to cause motion by itself, then it necessarily moves eternally and with an eternal uniform movement, like the Prime Mover.  Matter, then, in every body necessarily requires for its existence to be dressed with a form either near or far.  The fact about matter, as Plato says, is that due to its need and ugliness matter avoids manifesting itself, and so conceals itself as it were in any possible form.  And these states accompany matter when it is separated from form.  Let us see then what happens to form when it is abstracted, and how this happens.
 

The principle applicable to this is that when an individual specified body exists one points to it, because the form and the matter of this body have not at all any discrepancy between themselves in any way, whether potentially or actually.  hence, both of them are a single thing, that is, "this specified individual".  Everything is due to a certain inclination, and hence, when a thing exists separately from an other thing, the other in its turn inclines to be separable from it.
 

But the question how two things are actually not at all different from each other are potentially different is the same as the existence of the part in a continuos whole whose parts all alike.  For two parts in this whole are actually one but potentially different.  Difference only arises, on the one hand, due to form, and on the other, due to matter.  But how form and matter become one thing actually while being different potentially, potentiality being always only the matter, has been demonstrated in the Metaphysics.  Here, potentiality indicates something different from what is indicated by our expression Balkowa (in potentiality) in change, because the being of form here is not potentially different from matter in so far as when one of the two is changed the "aggregate" is decomposed, but in a different way.  For the form that characteristics this "aggregate" decays necessarily when the "aggregate" decays; and the matter assumes an other form, and through this reshaping there arises another aggregate.  But the relation of the second (second) form to the species of  the form exists in this process in the matter, and thus, through this relation the matter imitates that which is actual, as been shown elsewhere.

 But form cannot be set in motion in the same way as matter, so as to become different; but it is different by necessity.  How can the form, then, be different?  That form is not moved essentially is evident, because it is not divisible; that it is moved by accident is not impossible, as has been shown in the Physics.  But, how does form become through its accidental movement something, while the movement is accidental; and how does this state happen to form so as to become through it a different entity?

 We reply:  It is an agreed fact that nature does not do anything in vain, nor is there in the universe anything without a purpose at all.  And, every existent comes to be either for the sake of something else or for the sake of itself.  The aim of that which exists for the sake of something else is to be connected with that for the sake of which it exists.  Connection is either in existence, like the connection of the soul with body, and the connection of that which suffers change with that which causes change -- no matter whether the connection is by change, or by being acted upon, or habit and the like -- or it is the connection of matter, namely, the connection of a body with a body.  This is of various kinds:  first, the connection of the body with that which contains it, namely, connection in space, second, the connection of the moving body with the body that is moved.  As shown in Physics VII, the most prior of all these connections is the connection in space, since all that is changed has something to cause change.
 

Connection is said of the connection of being and the connection of body per prius et posterius.  Connection in space is essentially the connection of a body with a body.  The rest of the kind is the connection of a body with a body by accident.  It is clear that everything is either a body or in a body, or not at all a body nor in a body.  I mean by my expression "in a body" all that which needs for its existence a body, for it has been demonstrated that there is an existence which does not need, for its existence, a body, and that on the contrary, the body needs it for its existence, and that it is connected with the body in this way, as has been explained at the end of Physics VIII, and in the sixteenth book of the book of Animals.  New, "this" ("incorporated being") is neither a body nor is in a body; it cannot have any connection except in existence alone.  Hence, if there is a thing that exists for the sake of something else, and this something, for the sake of which the thing has come into being, is a body, then it is necessary that the former is connected with the latter corporeal, although the latter does not owe its existence tot he former so that the latter be in the former, as health in man.  "This" is then necessarily a body, because if it were not a body then there would be no connection between the former and the latter at all.
 

The immattered forms do not exist for their own sake, but are for the sake of something else, for nature does not make anything without  a purpose.  As shown in the book of Heavens and Earth, the elements are for the sake of the spherical bodies, because the spherical body is in the elements in the same way as the body is in space; and they are in the spherical body in the same way as a part is in the whole.  For the universe is like a single separate animal which requires nothing from outside at all.  Hence, the form of the elements, is necessarily in matter.  And, since the extreme cause, that is the final cause, is the most excellent being; hence, its being after the elements must necessarily be in substratum, because that for the sake of which the elements come to be is so.  For, if the spherical body were not necessarily in a substratum then the elements would not need be in a substratum.  hence, the existence of those forms in a substratum is the cause of the being of the elements in a substratum.  Thus, the body is said of those (the spherical bodies) and of these (i.e. elements) per prius et posterius, and this makes clear what has been doubted by Abu Nasr in his treatise on "the Intelligence and the Intelligible."

 It has been shown that matter, as assumed by Aristotle, exists only for the sake of the existence of form, but for the sake of the last existence of the form and not for the sake of its first existence; and the doubts has arisen only in so far as its first existence is concerned.
 Sometimes a doubt is expressed against this view and is said:  "The last existence is the best existence, the first existence of form being the most incomplete, and so, the corporeal being is better than the intelligible being.  This contradicts what Plato says and what is known of the doctrine of the Peripatetic."

 We reply:  "Our expression 'the best thing' is said in two ways.  First, in an absolute sense, then this is clear that the intelligible being is better than the sensible being, because the object of mind is more suited to existence than the object of sense, since the former is the principle of the latter, as has been demonstrated by Plato, Aristotle, and many other Peripatetic.  And what is the most suited to existence is called the best in existence.  Second, a being is sometimes called 'the best' in relation to different species of existing things, but not so that it is for the sake of that existent.  So that the term 'being' which belongs to the existent would not be from the genus of the best, and its best thing would only be from the genus of the last perfect being, this best being existing not in so far as it is the species of 'existence', but in so far as something characterizes it.  It is, therefore, said that the immattered form is intelligible not essentially but in so far as mind has made it.

 But, someone may doubt and say:  "If it were not inherent in the essence and existence of the being which is a property of the immattered forms that they are intelligible, they would not become intelligible, because everything exists for a purpose and it is in the nature of the thing to receive that purpose, and that which has not in its nature to receive anything, neither near nor far, cannot have anything neither essentially nor accidentally."
 We reply:  "That it is in the nature of the immattered forms to be somehow intelligible has been assumed in the argument; and that their being intelligible is in their particular being is not the case.  But it is through that of which they are constituted that they receive the intelligible existence, and when they are connected with the mover they obtain that beings, hence, they need something else in order to have that being.  This something is their connection with the mover which comes to them from outside.  Hence, it is not in their essence that they become intelligible, but it is something else which makes them intelligible.  Hence, they always; in order to become intelligible, need this connection which makes them entirely accomplished in existence.  So the perfection of their being which is peculiar to them would be from the genus of the imperfect being; and when they take their share from the best being they confine themselves to the best being.  It is for the sake of this that every (form) tries to be free from matter and is necessarily separable from it, as it is said of the 'Acquired Intellect' ".

 But someone may doubt this view and say:  "Forms being objects of mind is the same as their being actually unconnected.  It, therefore, follows that there is in nature something without a purpose.  Hence, the same doubt comes back."
 We reply:  "These immattered forms are sometimes sensible and imaginable, and are them movers of desire, anger and many other things.  They have, therefore, functions which are for them either in respect of their being in their particular matters, and so they are designated by their respective terms; or are in respect of their being sensible and imaginable, and so not designated by those terms.  But the genus is called "a soul set in motion', and there is no particular name for every particular kind of it."
 But someone may ask and say the same thing about their being intelligible (i.e. that which has been just now said about their being sensible and imaginable.)  Their being intelligible means that some of them do not actually exist at all.  But this doubt should only be investigated while considering the existence of the universe and the mutual relations of its parts.  For, the being of the intelligible for the sake of something else is different from the being of the material for the sake of something else, the two beings being, indeed, opposite to each other.  It is for this reason (i.e. the intelligible being is different from the material being) that Abu Nasr says:  "They become an existent of the universe."  Since the mover acts sometimes and does not act some other time, there must be a change by necessity here.  But the mover is not body, and the change is then in the immattered form.  And, since all that is not divisible is not changeable, change will happen to the immattered form by accident, that is, through a changeable.  So the immattered form necessarily always needs matter in order to be changed through it.  This connection is not to be called a change in space, because one of the two (connected) is not body, nor is it near nor far.  This connection is, therefore, only in its being.

 Hence, for a material thing there are two kinds of change, one preceding the other in the same way as they do in their principles.  One is "change in space", its principle being the material being in so far as it is in a substratum.  For the material being indicates it (i.e. change) in so far as it is becoming and not in so far as it is an existent.  The other change is for the sake of this being that is extraneous to its essence and precedes that other being just as the - movement - in - space precedes the other movements.  But the change in quantity, such as growth, is a characteristic of some material bodies that take nourishment.
 Change - in - being means that "this", for instance, is in a nearer stage in existence.  This is because this stage has a certain discrepancy in it.  We have already said that this is not possible concerning the immattered forms except for the sake of the mover, while the thing moved cannot cause motion.  It is, therefore, clear that existence must be mixed with the elements; its movement is sometimes caused by a mover homogeneous to it, as is the case in those animate bodies which are reproductive, and some are moved by the spherical bodies, e.g. the souls of those that are generated but are not reproductive.

 Since the discourse is concerning the existence of the immattered forms as separated from matter, namely, the "actual intellect", it is clear that this is the ultimate cause of all that we have said before.  This kind of existence in matter cannot exist actually unless it is in such states as are limited e.g. taking nourishment, and the most able being is the one free in taking suitable food as well as in the rest of that by which alone one's being is accomplished, namely, man.
 

Now, then, necessarily the faculty of reason precedes the rest of the faculties of the soul in existence, and the rest of the faculties exist for the sake of this faculty which is the best; and hence, the rest of the faculties and imagination are generated for the sake of the reasoning faculty.  This is not by necessity, as has been held by those who believe that since the elements get mixed together in equal proportion they cause sensation by chance.

 Form, then, has grades.  First grade is its existence in matter, and there is not at all any change in it.  This is the most extreme one, the other extreme being its opposite, namely, its being intelligible.  This is the most extreme side.  But, for being intelligible, it requires a material being of which it is constituted.  For that is the principle of its existence.  Perfection is of all principles the most deserving to be a principle, and so it is not at all possible for this form to be separated from matter.  Whenever it is separated it is a wrong contrivance.  hence, it follows necessarily that the study of nature must be concerned with "the forms with matter."  This will be explained in the discussion on the faculty of reason which is never without a substratum, since it is made so in its nature.  When form is found to be different it is evident that it is connected with a mover in proportion to its difference which depends upon the degree of abstraction.  The same applies to every immattered form, I mean, that is exist in its substratum in the sense that the substratum is its matter.  Thus, form and the elements are in one and the same grade.  But when form exists somehow separated from matter whether by being abstract or by having a substratum -- the state of its substratum in relation to being however is not like the state of matter in relation to form -- then however it may be, it is called perception.

 But the abstraction of the immattered form is not possible, because, as shown before, its relation to matter is in itself.  hence, necessarily there is, in the bodies possessing form, an "intention" by which the form is connected with the matter.  So, as long as it is connected with the matter it is intelligible, and when matter is changed it becomes intelligible potentially.

 This separation is of various grades, each grade being called a soul, and a psychical faculty while it is a grade.  To these belongs sense-perception, next imagination, next reasoning which is the extreme.  As for taking nourishment, what position it possesses, we shall soon explain later on.  We have already discussed for which purpose these grades exist.  All these are for the sake of the reasoning faculty.

 But that these are grades is self-evident, since sense-perception and imagination are things manifestly existent.  But, which of these grades is sense-perception, and how it comes to be, all these will be clear by when we shall say.
 We say:  It is evident that sense-perception is actual, like the state of an animal that is awake when it perceives; and sometimes potential, like an animal that sleeps and keeps his eyes closed.  Potentiality is either near or far -- far like the capacity of sense-perception in the embryo, and near like the sense of small when no object of smell is present, and like the sense of sight in darkness.  Similarly, it is generally admitted that no species does perceive anything by an organ at random.  Animals, for example, do not sense with their mouth nor taste with their eyes.

 All that is potential can only be actual when it is changed by something that causes change, as has been shown in Physics VIII.  Thus, it is necessary for sense-perception to have an object that suffers change and an agent that causes change.  It is clear that the object of movement is different form the mover.  The mover is then the object of perception and its being a mover is elf-evident, and the thing moved is the sense organ. Everything that is changed (moved) is potentially the thing into which it is changed, and so the sense has the potentiality of sense-perception, and, has been explain in many places, potentiality is in matter.  Let us therefore:  consider which matter should be this potentiality.
 

So, we say; Matter is predicated  per prius of the first and common transitory matter.  This matter is potentially that thing which it ought to receive.  Although it is in its essence without form, it is, as we have said, connected with a form, and, therefore, it takes always one of the contraries.  This is because the first forms which are forms of the substances, such as lightness and heaviness, are never without contraries.  The same applies to the accidents that are related to the bodies qua bodies, since matter possesses of the first accidents only one of the contraries, and the first of the accidents to exist in its extension ( = lengths).  Hence, matter always exists as corporeal.  But, the cause of the extension being the first accident inherent in matter has been given elsewhere.  Next, there are other kinds viz. quality, place and the rest of the ten categories which apply to the body.  Every form that is in matter then has necessarily extension.  For form belongs either to a simple body and, as has been said, has extension because of the matter, or belongs to matters which have extension.  And, in so far as it is a form at will necessarily have the kind of extension which it has, no matter whether the relations of its three dimensions to one another were determined, as in the case of animals, or whether it has them for the form accidentally, like a piece of gold, since a piece of gold may be globular having all three dimensions equal, and when it is extended and becomes oblong, its dimensions are nearer to one another.

 The sensible are accidents in material bodies, and are those that are peculiar to natural bodies or the forms of natural bodies.  The natural accidents are either characteristics of natural bodies, like heat, cold, hardness, and softness, or common to both natural and artificial bodies.  But they are for the artificial bodies per posterius and for the natural bodies per prius. The sensible are then forms in natural bodies, the accidents being taken as forms.  It is evident that all these are immattered forms, the forms of none of them being separable.
 Natural accidents are either movers or moved.  Movers, again, are either homogeneous tot he thing moved namely, the thing that becomes like them, like fire; or not homogeneous, like fire for hardening clay.

 That which is moved from its species however, does not become that mover nor acquires the form that is peculiar tot he mover in so far as it is that mover.  Hence, the natural attributes are set in motion towards the species.  Now if they were moved towards that particular individual of the species of the mover it would not be possible for it to change ( = move) a single piece of wood, but their movement is caused by fire itself, like the movement of the lover for the beloved.  For this movement does not set any man in motion at random, for example, a man qua man; and this is self-evident.

 Hence it is clear about the mover that it moves not because it is that which is in matter in so far as it is in matter, but it moves in so far as it is that species, as is observed in the mixed bodies which are set in motion by the movement of the dominating part without having, at the time of mixing, any choice.  Nor is there any discrepancy except if there are two contraries (to be mixed).  But here there is only one contrary, and matter has no meaning in it; but it is in the body as though it were a non-existent, and form were alone in the body; its nature has already been explained as we mentioned while discussing change.  Buthtis being is not the same through which change has occurred, but is the being of the form that characterizes it for the sake of its essence.

 Now if this form exists while being separated from the matter in the way we described then the form must be in one of the two ways:  either it is so that it had been a different changed existent and then appeared to perception -- this is evidently absurd, for it necessarily follows from this that the form of "this particular scribe," for instance, must be present to the sense organ before the perception of the object of sense --, or it is so that it is in the process of becoming, which necessarily entails of its being potentially before.  And what is potential is matter.  But if this matter belongs to the one "becoming" then the one becoming is the same as the object, because it necessarily follows that the "becoming" must be a body, and in sense-perception it will have size in itself.  Thus, the small will not stimulate that which is greater than it, otherwise the part will not be smaller than the whole which is absurd.
 If at all, matter is only connected with the mover by a connection different from the first connection.  If matter is in a different state so that when it is in a certain state the mover is connected with it, and when in a certain other state it is not connected with it --  this state being the soul -- or, there are matters of not a single species, then, how can a matter be without form at all?  How can that whose nature is this be moved, and how did it come to be?  For this mover is connected with his object of movement in a  way different from the way it is connected with matter so that the forms would start to receive, since we cannot hold that sensation moves the sensible.  If we held what Galen held concerning sights then the sensible would act and would surely be separable.  But Galen maintains that the moved mover moves towards the mover, namely, the sensible, while Aristotle ascertains that the mover here is the sensible which is moved in a  way towards the thing moved, because the mover must be actual.  This is self-evident.  And this potentiality, in general, is the soul.
 Since the facts are, as has been shown, (we say:) everything that is becoming and perishable is a tangible body.  All tangible body is either simple or compound.  The simple bodies are the four which have been enumerated in many places -- one of these places being in the twelfth book of the book of Animals.  As has been shown, every sentient body is compound and not simple, and as described, it is made of earth in order to have a stature and a specific limit, because there is no animal having parts similar to each other and to the whole, nor any plant.  Everything that is composite has its elements of which it is composed either actually in it -- its composition being then either by contiguity or by coalescence, and in general, joined together -- or in potentiality, its composition being then mixture.  Everything that possesses soul is composed in this way and not in any of the other ways.  For there is no plant  nor any animal in which any of the elements exists actually, and so there is not one element manifest in it in a way as to believe that "this" is one of the two, as is ascertained in the case of many compound things, like many stones and many mineral bodies.  On the contrary, earth and water are the only elements that are found in plants and animals mixed together.  But the rest of the elements is sometimes hidden one in the other.

 All that is mixed has an agent to mix it, and how simply mixing takes place has been shown in the De Generations et Corruptione.  Mixing is either artificial, like the mixing of gold and silver; and of honey and of vinegar in oxymel; or natural as the mixing of the elements in plants.  As shown, natural mixing is caused by action and by "being acted upon."
 The kinds of change by which each single kind of mixing takes place are either boiling, putrefaction or some other kinds of those enumerated in Meteorology IV.  All these kinds are completed by natural heat which is necessarily in a natural body because heat is a separable thing.  This heat is not in one of the elements  since if it were in it, it would necessarily require to be moved in space together with an other element so that they would eventually meet each other, because meeting precedes mixing.  Now, if the mover of both or of one of them does not move in order to mix them then it is an accidental mixing.
 Sometimes mixing takes place and sometimes not, because the cold element is sometimes inefficient in capacity so that it cannot move the other element which is hot; then the hot element moves it or makes it like itself.  This is, however, genesis and not mixing.  And, sometimes, it takes place according to each of them moving the other, but this does not happen always in one and the same relation, and so it produces various kinds of mixing.  Hence, when the matter happens according to order it needs necessarily a mover from without.
 

The artificial mixing is included in this kind, and it is through this kind of mixing only that the mixed object always becomes potentially a medium between the things which constitute the mixture.  For the one that mixes and moves the object of mixing in this way makes the mixed thing stop in one of the intermediaries; and the thing mixed becomes intermediary things only because it is homogeneous tot he elements.

But when the agent that causes mixing is "warmth" which is homogeneous to the "heat" of the elements then it causes something like boiling ( = concoction ) that produces mineral bodies provided it so happens that the matter is suitable for being boiled.  This kind of mixing resembles the artificial mixing that employs fire, as e.g.  the part mixed of earth and water.  In this mixing things become manifest which are not to be found in the elements, as condensation and rarefaction, as it happens in the case of gold; and similar to this accident are odors and flavors, and the different colors, and in short, the bodily states that spread over the body and are divided by its division.  It follows necessarily then that they must have parts similar to each other and to the whole, because boiling sometimes occurs in them.  This kind of mixing which is not like the first.  Hence, spherical movements does not produce a mineral body and, in general, a body having its parts alike, except in special places, because mineral bodies are not produced but from a mine.  A mine is a place in the cavity of the earth where a body having parts similar to one another is generated through vapor and smoke that are confined to it in order tot hicken that part of the earth which boils by the heat that is in the part itself.  It is therefore that there is not at all in all the three places enumerated in the Meteorology any organic body.
 

Then, the things produced by mixing that exist with this kind of fetidness can only exist having different elements.  All this is either a natural form, or accidents in natural bodies to be found in the definition of the near mover.  Then, the things produced by mixing that exist with his kind of fetidness can only exist having different elements.  All this is either a natural form, or accidents in natural bodies to be found in the definition of the near mover.
 But in that which is composed of the elements, which is moved by the heavenly bodies, and in general, that which is moved by locomotion which causes meeting, the near and the far mover are one and the same, namely, the spherical body, since it moves by nature and essentially.  But the near mover in what is produced by broiling is the heat by which broiling takes place, and the far mover is the body that is moved in a circle.  Hence, in what is produced by broiling the near mover from the elements is either one of the elements, namely, fire, or that which is composed of fire.  All these are sensible things, either primary like colors, or secondary, like extension ( = lengths ), shapes and forms of natural substances.  All these are things which exist in matter, and when they are in matter they become with the matter one in number and different in potentiality, as we have described before. None of these things can have sense-perception.  The primary matter is each and every one of these potentially.  Everything that becomes one with matter belongs to the matter either primarily, or secondary, or thirdly.  Those forms that belong to the matter either primarily, or secondarily, or thirdly.  Those forms that belong to matter essentially are necessarily substances, because the rest of the matter that exists depends only on the forms of substances, and hence, they need alteration when they are generated.  For matter is not at all anything in actuality, but the thing that suffers change necessarily exists as a motion it necessarily exists, requires a form and undergoes a change in the accident, and it exists through the form that is in it.  This causes change in form just as the movement of place causes change of positions.  For movement was not in the position, but position is caused through movement.  If, however, movement were in the form then matter itself would be moved, and, thus, would become a certain thing.  But in the case of alternation the matter is moved by accident.
 

As we have said, all that exists in the natural bodies whether element or mineral, is material and united with matter.  But plants and animals have those material states which belong tot he elements, like the material states that are caused by broiling.  These states bring into being those bodies that have parts similar to one another and are constituted of the elements.  Besides, animals and plants have some other states which do not belong tot he elements nor are caused by broiling of the elements.  This is the forming of a new thing which is evident in most of plants, and is clearer in animals, and they have parts similar to each other because they are organs.

 The mover that causes this motion of matter, namely, the creation of a new thing is a different kind of mover.  This is evident by a slight consideration.  As shown in Physics VIII, this mover is not the spherical movement although it is not without it.  But the mover seeks only the particular essential movement which is the near one.  This mover is, therefore, not the broiling heat, but the broiling heat as its organ, and hence, flavor, smell and the rest of the accidents caused by broiling are inherent bodies.  But how these accidents are caused by the broiling heat has been explained in Meteorology IV.  These accidents therefore necessarily give rise to the forming of a new thing.
 

In that which has such a principle, at the time when it is generated, the mover must necessarily be mind.  But this view is more suitable tot he genesis of animate beings, as has been summarized in the seven-teenth book of the book of Animals.

 That which has this principle is of two kinds:  one kind connected with its organ by which it causes motion, as for instance, the animal that propagates itself.  This is the semen, because the semen is a body that generates the animate.  And it is evident that the heat of the semen through which the semen acts is in it.  As to the other kind, its organ by which it is moved is in something else.  This applies to those animals which are said to be generated spontaneously.  The organ that belongs to a kind like this is the heat of putrefaction or some other heat.  This kind somehow resembles the productive art, because the organs of art are outside the body to which the art is applied.  Hence, it causes motion through moving the elements and mixing.

 This heat continues to move the earth which is mixed with water until when the whole has reached a state in which it can receive that form, it receives it eventually.  It is evident that with the beginning of motion it starts to receive the form.  Receiving and moving corresponding mutually with each other.  The soul when perfected receives the form of the mixture and receives it through the "mixing" it possesses.  The form which the mixed bodies receive either does not move anything essentially, but is received, and this is like the forms of the minerals.  And again, this form precedes in matter that which exists in the matter through the form like the states that characterize the gold in so far as it is gold, e.g. rarefaction and endurance to the fire.  Or it moves the body that contains it with a movement peculiar to the body, as for instance, the soul of the plant.  For when matter receives the form of a definite body it moves that body together with itself.  Here are then necessarily immattered faculties some of which are far, for example, the power of the elements, and some near, as for example, the power of the mixed body which is always found only connected with form and so it is always substratum.  Hence, for the animate there is no opposite, because this form has no particular privation.  There is a privation only of that form, as for instance, you say:  "The form of the bee."  Now, some of the forms have "far matter," as is said of the water "extremely hot."

 As to the near faculty, it is never without form, because it is always a substratum and is not at all separable.  Hence, it is likely that the form of the mineral is in its matter, because it has no contraries nor opposing privations e.g. the opposition of privation to habit.
 In such cases the form of "mixing" is the quiddity of that body, as for instance, gold.  For the mixed object is the matter and its existence is the species of condensation.  It is evident that this condensation is in the near matter which is in the mixed object like the form for the natural composition (mixing).  This matter then receives that condensation, but since the matter is not at all separable from this form, the "aggregate" of all these is always like a single thing, matter being manifest in existence only at the time of change.  All these are forms in the matter through which the "aggregate" becomes a single thing, since this is the meaning of matter's receiving forms that arise in matter.  But when the form becomes different, and this is only when it is separated in a way, then it is different from matter.
 If the difference is caused by what takes place then it necessarily follows that it is through a preceding change either in the form or in another substratum, as has been shown in Physics VIII.

 But form cannot suffer change, since all that is changed is divisible and form has no parts nor is body.  And hence, change occurs in a different thing.  Thus form, through changing from this form, acquires a limited relation.  So, form is changed by accident -- its change being in a moment just as it happens to that which is related.  For, although being greater, if AB is not twice of JD then JD is necessarily only a half, and AB twice without having been changed in itself; it remains rather in its state as it has been, but is changed from one relation to another relation.

 All change, as explained in Physics VIII, is in quantity, in quality, in place, or depends on one of these.  But when form is separated from matter, that same form exists actually, while being what it is, separated in an existence peculiar to it, and is different from that which it was while being in the matter which received it.  Now, had it existed without having come to be then this would entail necessarily an absurdity, namely, that the form of a specified individual should exist before it exists either in sense-perception and imagination -- which is impossible -- or in mind -- which is assumed to be possible; but we shall explain this when we shall investigate about the rational faculty.

 Now, it is clear that sensation has an origin.  All that has origin potentially before it comes to be.  But how is it possible for sensation to be a separate form as well as to "become," since "becoming" concerns matter only?  We answer:  Our expression "matter" applied to the faculties of the soul as well as to the faculties of the body is equivocal, because matter exists in the bodies only by being specified by this form, so that they both become a single thing that demands the performance of the action that is that this existing thing should perform, by nature as has been explained before this.  By the expression "matter" in this place, we mean only the reception of the form through which the body which has a potency like this becomes sentient, since both the material faculty and the faculty which is out accept color, and color is form in the matter -- color and matter being one thing -a "this color" on its own has no existence at all.  Color in the faculty of sensation is that which exists with what characterizes it.  It has left its matter and become a definite thing.  Hence, it is not possible for matter to receive two contraries like whiteness and blackness, the two contraries, because if it were to receive the two contraries, then the two contraries would surely be in matter, and there would be no contrariety between them at all, but they are essentially contraries, for they are essentially two forms, each of them or both forms different from each other.  Hence, it is not possible for them to exist except in two ways.  That they are in two substrata is possible; but if they are in one substratum, then they must be in it in two different moments without meeting in one substratum.  Since they are in the sensitive faculty as two separate beings their co-existence is not impossible; what is impossible is only their being together in one substratum, and not that they cannot co-exist in a genus, and in general, in the faculties of the soul.  But this exists materially only in colors.  For one and the same air, for example, is between white and black at the same time.  This is because their forms are not in the same way in air as form is in matter, but are in a way intermediate between the material reception and the reception of the physical faculty.
 

Since faculty are defined by relations of the substratum to the habit and the faculties are distinguished through this from each other in their essence, the sensitive faculty is a preparedness in the sense organ which becomes the form of the thing perceived.  So, the "meaning" is the form separated from matter.  Hence, the physical faculty must receive the "meaning" while it is a "meaning," and that which receives is a "meaning" in potentiality.  Similarly, the perception of the soul is in no way a passive state.  But whether it comes to be by "being acted upon," we shall soon explain latter on.  It is therefore sometimes assumed that the one that is "being acted upon" receives form alone, and that when the potentiality hot, for example, becomes actually hot it does not receive the "meaning" of that which is in the mover, although things are from the mover, as we said before.  It receives only an other hot and so it becomes a different "hot" resembling the first, while there is no relation between that is one of the two and the heat that is in the other in any way.  The only relation between them is this, that their respective forms when separated become one in number.  As to the difference between their two individual forms, if it is permissible to call the individual of heat a form, there is no difference between these two forms and the matter when it becomes an individual, as has been summarized somewhere else.  Hence, in saying "the heat of the one of the two" we do not mean that it is with its matter so that the individual of the "heat" itself should be in the soul.

 Since the "meaning" of the thing is the thing and since the meaning of "thing" is its actual existence, it means to us when the meaning of an individual reaches us that we have perceived the individual through that faculty that belongs to us.  It is evident that the perceptions of the material beings we acquire are transitory.  If they were not transitory then they would be eternal.  But if they were eternal it would necessarily imply that Zayd, for example, was before Zayd, and "this hot" was before "this hot"; it will also imply that they are moved in space, and other similar absurdities.

 Again, it is generally admitted that sensations are transitory.  This can be ascertained if we give some slight attention to it.  All that is transitory has existed potentially before its actual existence.  As we said before, possibility and potentiality are inter-dependent.  This potentiality is then necessarily in a matter, and this matter is the matter of the like of this being.  And, customarily it is called spiritual and non-corporeal, or similar terms are used, and hence, it does not become a body when perceived, because body is there only when the form is not at all different -- this is so when it is not separated.

All information was extracted from:
 1.  MS Hassan Ma’sumi.  Ibn Bajjah’s "Ilm-al-Nafs".  Published by Hital Books, 1975.