LESSON 9

Parts of the Quiddity and Definition. Priority of Parts to Whole

Chapter 10: 1034b 20-1035b 3

             622. But since the definition is the intelligible expression of a thing, and every intelligible expression has parts, and just as the intelligible expression is related to the thing, so is a part of the intelligible expression to a part of the thing, the problem now arises whether the intelligible expression of the parts must be present in the intelligible expression of the whole or not; for in some cases they seem to be and in others they do not, for the intelligible expression of a circle does not include that of its segments [but the intelligible expression of a syllable includes that of its letters], yet a circle is divided into segments as a syllable is into elements.

             623. Further, if parts are prior to a whole, and an acute angle is a part of a right angle, and a finger a part of a man, an acute angle will be prior to a right angle, and a finger prior to a man. However, the latter seem to be prior, for in the intelligible expression the parts are explained from them; and wholes are prior because they can exist without a part.

             624. Or perhaps it happens that the term part is used in many senses, one of which is what measures a thing quantitatively. But let us dismiss this sense of the term and inquire about those things which constitute the parts of which substance is composed. Now if matter is one of these, and form another, and the thing composed of these a third, then there is one sense in which even matter is called a part of a thing, and there is another in which it is not, but only those things of which the intelligible expression or specifying principle consists. For example, flesh is not a part of concavity, because flesh is the matter in which concavity is produced; but it is a part of snubness. And bronze is a part of the whole statue, but it is not a part of the statue in the sense of form; for predications must be made according to a thing's form and insofar as each thing has a form, but the material principle should never be predicated of a thing essentially. And this is why the intelligible expression of a circle does not contain that of its segments, whereas the intelligible expression of a syllable does contain that of its letters; for the letters are parts of the intelligible expression of the form, and are not matter. But segments of this kind are parts of the matter in which the form is produced, yet they are more akin to the form than bronze is when roundness is produced in bronze. However, not all the elements of a syllable will be contained in its intelligible expression; for example, the letters inscribed in wax or produced in the air; for these are already parts of the syllable as its sensible matter. For even if a line when divided is dissolved into halves, or a man into bones and sinews and flesh, it does not follow for this reason that they are composed of these as parts of their substance, but as their matter; and these are parts of the concrete whole, but not of the specifying principle, or of that to which the intelligible expression belongs. Hence they are not included in the intelligible expression of these things. Therefore in some cases the intelligible expression of a thing will include that of such parts as those mentioned, but in other cases it need not include them unless taken together they constitute the intelligible expression of the thing. For it is by reason of this that some things are composed of these as the principles into which they are dissolved, while others are not. Hence all things which are matter and form taken together, as snub and brazen circle, are dissolved into these parts, and matter is one of them. But all things which are not conceived with matter but without it, as the intelligible expression of form alone, are not corrupted either in an unqualified sense or in such a way as this. Hence these material parts are the principles and parts which come under these, but they are neither parts nor principles of the form. Therefore a statue made of clay is dissolved into clay, and a sphere into bronze, and Callias into flesh and bones; and again a circle is dissolved into its segments, because it is something conceived with matter. For the term circle is used equivocally both of that which is called such without qualification and of an individual circle, because there is no proper name for individual circles.

COMMENTARY

             1460. Having shown what the quiddity (or essence) of a thing is, and to what things it belongs, and how it is related to the things to which it belongs, and that it is not necessary to posit separate quiddities in order to account for the generation of things, here the Philosopher's aim is to expose the principles of which a thing's quiddity is composed. This is divided into two parts. In the first (622:C 1460) he describes the principles of which a thing's quiddity is composed; and in the second (640:C 1537) he explains how the thing which comes into being from these principles is one ("And now").

             The first part is divided into two. In the first he raises a difficulty. In the second (624:C 1467) he solves it ("Or perhaps").

             The first part is divided into two insofar as he raises two difficulties about the same point. The second (623:C 1464) is treated where he says, "Further, if parts."

             He accordingly says, first (622), that every "definition is the intelligible expression of a thing," i.e., a certain combination of words arranged by reason. For one word cannot constitute a definition, because a definition must convey a distinct knowledge of the real principles which come together to constitute a thing's essence; otherwise a definition would not adequately expose a thing's essence. And for this reason it is said in Book I of the Physics that a definition divides "the thing defined into its separate elements," i.e., it expresses distinctly each of the principles of the thing defined, and this can be done only by means of several words. Hence one word cannot be a definition, but it can give us information about something in the same way that a word which is better known can give us information about a word which is less well known. Now every intelligible expression has parts, because it is a composite utterance and not a simple word. Therefore it seems that, just as the intelligible expression of a thing is related to the thing, so also are the parts of the intelligible expression related to the parts of the thing. And for this reason the problem arises whether the intelligible expression of the parts must be given in that of the whole or not.

             1461. This difficulty is confirmed by the fact that in some intelligible expressions of wholes the intelligible expressions of the parts seem to be present, and in some not; for in the definition of a circle the definition "of the segments of a circle" is not present, i.e., the definition of the parts which are separated from the circle, as the semicircle and quarter circle; but in the definition of a syllable the definition "of its elements," i.e., its letters, is present. For if a syllable is defined it is necessary to say that it is a sound composed of letters; and so we give in the definition of a syllable the letter and, consequently, its definition, because we can always substitute the definition for the word. Yet a circle is divided into segments as its parts, just as a syllable is divided "into its elements," or letters.

             1462. Now his statement here that a part of the definition of a thing is related to a part of the thing as the definition is related to the thing, seems to involve a difficulty; for the definition is the same as the thing. Hence it seems to follow that the parts of the definition are the same as the parts of the thing; and this seems to be false. For the parts of the definition are predicated of the thing defined, as animal and rational are predicated of man, but no integral part is predicated of a whole.

             1463. But it must be remarked that the parts of a definition signify the parts of a thing inasmuch as the parts of a definition are derived from the parts of a thing, yet not so that the parts of a definition are the parts of a thing. For neither animal nor rational are parts of man, but animal is taken from one part and rational from another; for an animal is a thing having a sentient nature, and a rational being is one having reason. Now sentient nature has the character of matter in relation to reason. And this is why genus is taken from matter and difference from form, and species from both matter and form together; for man is a thing having reason in a sentient nature.

             1464. Further, if parts (623).

             Then he gives the second difficulty; and this has to do with the priority of parts. For all parts seem to be prior to a whole as simple things are prior to what is composite, because an acute angle is prior to a right angle, since a right angle is divided into two or more acute angles, and in the same way a finger is prior to a man. Hence it seems that an acute angle is naturally prior to a right angle, and a finger prior to a man.

             1465. But, on the other hand, the latter seem to be prior; namely, a right angle seems to be prior to an acute angle, and a man to a finger, and this seems to be so for two reasons. First, they are prior in meaning; for in this way those things which are given in the intelligible expression of other things are said to be prior to them, and not the other way around; "For in their intelligible expression an acute angle and a finger are explained from these," i.e., they are defined in reference to these, namely, to man and to right angle, as we have stated. Hence it seems that a man and a right angle are prior to a finger and to an acute angle.

             1466. Second, some things are said to be prior because they can exist without others, for those things which can exist without others, and not the reverse, are said to be prior, as is stated in Book V (465:C 950); for example, the number one can exist without the number two. Now a man can exist without a finger, but not a finger without a man, because a finger which has been severed from the body is not a finger, as is stated below (626:C 1488). Hence it seems that a man is prior to a finger; and the same reasoning applies to a right angle and to an acute angle.

             1467. Or perhaps (624).

             Then he solves the difficulties which were raised; and this is divided into two parts. In the first he gives the solution. In the second (625:C 1482) he explains it ("The truth, then"). In the third (629:C 1501), he settles a problem that could arise from the foregoing solution ("Now the problem").

             In support of what has been said in this chapter it should be noted that there are two opinions about the definitions of things and their essences. Some say that the whole essence of a species is the form; for example, the whole essence of man is his soul. And for this reason they say that in reality the form of the whole, which is signified by the word humanity, is the same as the form of the part, which is signified by the word soul, but that they differ only in definition; for the form of the part is so designated inasmuch as it perfects the matter and makes it to be actual, but the form of the whole is so designated inasmuch as the whole which is constituted by it is placed in its species. And for this reason they think that no material parts are given in the definition which designates the species, but only the formal principles of the species. This appears to be the opinion of Averroes and of certain of his followers.

             1468. But this seems to be opposed to the opinion of Aristotle; for he says above, in Book VI (535:C 1158), that natural things have sensible matter in their definition, and in this respect they differ from the objects of mathematics. Now it cannot be said that natural substances are defined by something that does not pertain to their being; for substances are not defined by addition but only accidents, as was stated above (587:C 1352). Hence it follows that sensible matter is a part of the essence of natural substances, and not only of individuals but also of species themselves; for it is not individuals that are defined but species.

             1469. And from this arises the other opinion, which Avicenna entertains. According to this opinion the form of the whole, which is the quiddity of the species, differs from the form of the part as a whole differs from a part; for the quiddity of a species is composed of matter and form, although not of this individual matter and this individual form; for it is an individual, such as Socrates or Callias, that is composed of these. This is the view which Aristotle introduces in this chapter in order to reject Plato's opinion about the Ideas, for Plato said that the forms of natural things have being of themselves without sensible matter, as though sensible matter were in no way a part of their species. Therefore, having shown that sensible matter is a part of the species of natural things, he now shows that there cannot be species of natural things without sensible matter; for example, the species man cannot exist without flesh and bones; and the same is true in other cases.

             1470. Now this will constitute the third method by which the Ideas are rejected; for Aristotle rejected them, first, on the grounds that the essence of a thing does not exist apart from the thing to which it belongs; second, on the grounds that forms existing apart from matter are not causes of generation either in the manner of a generator or in that of an exemplar. And now in this third way he rejects Plato's thesis on the grounds that the intelligible expression of a species includes common sensible matter.

             1471. Hence in solving this difficulty (624) he says that the word part is used in several senses, as was explained in Book V (515:C 1093); for example, in one sense it means a quantitative part, i.e., one which measures a whole quantitatively, as half a cubit is part of a cubit, and the number two is part of the number six. But this type of part is at present omitted, because it is not his aim here to investigate the parts of quantity, but those of a definition, which signifies a thing's substance. Hence it is necessary to investigate the parts of which a thing's substance is composed.

             1472. Now the parts of substance are matter and form and the composite of these; and any one of these three--matter, form and the composite--is substance, as was stated above (569:C 1276). Therefore in one sense matter is part of a thing, and in another sense it is not, but this is true "of those things of which the intelligible expression or specifying principle consists," i.e., the form; for we understand concavity as form and nose as matter, and snub as the composite. And according to this, flesh, which is the matter or a part of the matter, is not a part of concavity, which is the form or specifying principle; for flesh is the matter in which the form is produced. Yet flesh is some part of snub, provided that snub is understood to be a composite and not merely a form. Similarly, bronze is a part of the whole statue, which is composed of matter and form; but it is not a part of the statue insofar as statue is taken here in the sense of the specifying principle, or form.

             1473. And to insure an understanding of what the specifying principle is and what the matter is, it is necessary to point out that anything which belongs to a thing inasmuch as it has a specific form belongs to its specific form; for example, inasmuch as a thing has the form of a statue, it is proper for it to have a shape or some such quality. But what is related to a form as its matter must never be predicated essentially of a form. Yet it must be noted that no kind of matter, be it common or individual, is related essentially to a species insofar as species is taken in the sense of a form, but insofar as it is taken in the sense of a universal; for example, when we say that man is a species, common matter then pertains essentially to the species, but not individual matter, in which the nature of the form is included.

             1474. Hence it must be said that the definition of a circle is not included in "the definition of its segments," i.e., the parts divided from a circle, whether they be semicircles or quarter circles. But the definition of a syllable includes that "of its elements," or letters; and the reason is that "the elements," or letters, are parts of a syllable with reference to its form, but not to its matter; for the form of a syllable consists in being composed of letters. The divisions of a circle, however, are not parts of a circle taken formally, but of this part of a circle, or of these circles, as the matter in which the form of a circle is produced.

             1475. This can be understood from the rule laid down above; for he had said that what belongs essentially to each thing having a form pertains to the form, and that what belongs to the matter is accidental to the specific form; but it belongs essentially to a syllable, which is composed of letters. Now the fact that a circle may be actually divided into semicircles is accidental to a circle, not as a circle, but as this circle, of which this line, which is a material part of it, is a division. Hence it is clear that a semicircle is part of a circle in reference to individual matter. Therefore this matter, i.e., this line, is more akin to the form than bronze is, which is sensible matter, when roundness, which is the form of a circle, is produced in bronze; because the form of a circle never exists apart from a line, but it does exist apart from bronze. And just as the parts of a circle, which are accidents in reference to individual matter, are not given in its definition, in a similar fashion not all letters are given in the definition of a syllable, i.e., those which are parts along with matter, for example, those inscribed in wax or produced in the air, since these are already parts of a syllable as sensible matter.

             1476. For not all the parts into which a thing is corrupted, when it is dissolved, must be parts of its substance; because even if a line when divided is dissolved into two parts, or a man into bones, sinews, and flesh, it does not therefore follow, if a line is thus composed of halves, or a man of flesh and bones, that these are parts of their substance; but these things are constituted of these parts as their matter. Hence these are parts of "the concrete whole," or composite, "but not of the specifying principle," i.e., the form, or "of that to which the intelligible expression belongs," i.e., of the thing defined. Therefore no such parts are properly given in the intelligible expressions of these things.

             1477. Still it must be noted that in the definitions of some things the intelligible expressions of such parts are included, i.e., in the definitions of composite things, of which they are the parts. But in the definitions of other things this is not necessary, i.e., in the definitions of forms, unless such forms are taken along with matter. For even though matter is not part of a form, it must be given in the definition of a form, since the mind cannot conceive of a form without conceiving matter; for example, organic body is included in the definition of soul. For just as accidents have complete being only insofar as they belong to a subject, in a similar fashion forms have complete being only insofar as they belong to their proper matters. And for this reason, just as accidents are defined by adding their subjects, so too a form is defined by adding its proper matter. Hence when matter is included in the definition of a form, there is definition by addition, but not when it is included in the definition of a composite.

             1478. Or his statement "unless taken together they constitute the intelligible expression of the thing" exemplifies his remark that "in other cases it need not include them." For in such cases it is not necessary that the material parts should be included in the definition, i.e., in the case of those things which are not taken together with matter, or which do not signify something composed of matter and form. This is evident; for since matter is not included in the intelligible expression of some things but is included in that of others, there can be some things which "are composed of these as the principles into which they are dissolved," i.e., the parts into which things are dissolved by corruption. And these are the things whose definitions include matter. But there are some things which are not composed of the foregoing material parts as principles, as those in whose definitions matter is not included.

             1479. And since matter is included in the definitions of those things which are taken together with matter but not in those of others, "hence all things which are matter and form taken together," i.e., all things which signify something composed of matter and form, such as snub or brazen circle, such things are corrupted into material parts, and one of these is matter. But those things which are not conceived by the mind with matter but lack matter altogether, as those which belong to the notion of the species or form alone, these are not corrupted "in such a way as this," i.e., by being dissolved into certain material parts. For some forms are corrupted in no way, as the intellectual substances, which exist of themselves, whereas others which do not exist of themselves are corrupted accidentally when their subject is corrupted.

             1480. Hence it is evident that material parts of this kind are the principles and parts of those things "which come under these," i.e., which depend on these, as a whole depends on its component parts; yet they are neither parts nor principles of the form. And for this reason when a composite, such as a statue made of clay, is corrupted, "it is dissolved into its matter," i.e., into clay, as a brazen sphere is dissolved into bronze, and as Callias, who is a particular man, is dissolved into flesh and bones. Similarly a particular circle depending on these divided lines is corrupted into its segments; for just as Callias is a man conceived with individual matter, so too a circle whose parts are these particular segments is a particular circle conceived with individual matter. Yet there is this difference, that singular men have a proper name, and therefore the name of the species is not applied equivocally to the individual, but the term circle is applied equivocally to the circle "which is called such in an unqualified sense," i.e., in a universal sense, and to singular particular circles. And the reason is that names are not given to several particular circles but they are given to particular men.

             1481. Moreover it must be noted that the name of the species is not predicated of the individual in the sense that it refers the common nature of the species to it, but it is predicated of it equivocally, if it is predicated in such a way that it signifies this individual as such; for if I say "Socrates is a man," the word man is not used equivocally. But if this word man is imposed as a proper name on some individual man, it will signify both the species and this individual equivocally. It is similar in the case of the word circle, which signifies the species and this particular circle equivocally.