Commentary Aristotle Physics
Lecture 4
Physics considers not only matter but also every form existing in matter
Since “nature” has two senses, the form and the matter, we must investigate its objects as we would the essence of snubness. That is, such things neither are independent of matter nor can be defined in terms of matter only.
Here too, indeed, one might raise a difficulty. Since there are two natures, with which is the physicist concerned? Or should he investigate the combination of the two? But if the combination of the two, then also each severally. Does it belong then to the same or to different sciences to know each severally?
If we look at the ancients, physics would seem to be concerned with the matter. (It was only very slightly that Empedocles and Democritus touched on the forms and the essence.)
But if, on the other hand, art imitates nature, and it is the part of the same discipline to know the form and the matter up to a point—for instance, the doctor has a knowledge of health and also of bile and phlegm, in which health is realized, and the builder both of the form of the house and of the matter, namely that it is bricks and beams, and so forth—if this is so, it would be the part of physics also to know nature in both its senses.
Again, “that for the sake of which the thing comes to be,” or the end, belongs to the same department of knowledge as the means. But the nature is the end or “that for the sake of which.”
For if a thing undergoes a continuous change and there is a stage that is last, this stage is the end or “that for the sake of which.” (That is why the poet was carried away into making an absurd statement when he said, “he has the end for the sake of which he was born.” For not every stage that is last claims to be an end, but only that which is best.)
For the arts make their material (some simply make it, others make it operative), and we use everything as if it was there for our sake. (We also are in a sense an end. “That for the sake of which” has two senses; the distinction is made in the Metaphysics.)
Therefore, the arts that govern the matter and have knowledge are two: the art that uses the product, and the art that directs the production of it and is architectonic.
That is why the using art also is in a sense architectonic; but it differs in that it knows the form, while the art that is architectonic as being concerned with production knows the matter.
For the navigator knows and prescribes what sort of form a helm should have, but the ship builder knows from what wood it should be made and by means of what operations.
In the products of art, however, we make the material with a view to the function, while in the products of nature the matter is there all along.
Again, matter is a relative term: to each form there corresponds a special matter.
How far, then, must the physicist know the form or essence? Up to a point, perhaps, as the doctor must know sinew or the smith bronze (that is, until he understands the purpose of each);
and the physicist is concerned only with things whose forms are separable indeed but do not exist apart from matter. Man is begotten by man and by the sun as well. The mode of existence and essence of the separable it is the business of the primary type of philosophy to define.
166. Having shown the difference between natural science and mathematics, the Philosopher here explains that to which the consideration of natural science extends.
Concerning this, he makes two points.
First, he shows that it pertains to natural science to consider both form and matter;
second, at “how far then” (194b9; [175]), he points out the limits of natural science in its consideration of form.
Concerning the first part, he makes two points.
First, he draws his conclusion from what has gone before;
second, at “here too, indeed” (194a15; [168]), he raises difficulties against his own position.
167. He therefore says first (194a12) that, since nature is said in two ways—namely, of the matter and of the form, as was said above—so must it be considered in natural science. Thus, when we consider what the snub is, we not only consider its form, its curvature, but we also consider its matter, namely, the nose. Hence, in natural science, nothing is considered without sensible matter, in respect both to matter and to form.
And it must be noted that this argument of Aristotle includes two approaches.
In one way, we can argue as follows. The natural philosopher ought to consider nature. But nature is both form and matter. Therefore, he ought to consider both matter and form.
The other way is as follows.
The natural philosopher differs from the mathematician, as was said above, because the consideration of the natural philosopher is like the consideration of the snub, whereas that of the mathematician is like the consideration of the curved.
But the consideration of the snub is a consideration of the form and the matter. Therefore, the consideration of the natural philosopher is a consideration of both.
168. Next, at “here too, indeed” (194a15), he raises two questions about what he has just said.
The first is as follows. Since “nature” is used for matter and form, is natural science about the matter alone, or the form alone, or about that which is a composite of both?
The second problem is as follows. Supposing that natural science does consider both, is it the same natural science that considers form and matter, or are there different sciences that consider each?
169. Next, at “if we look at the ancients” (194a18), he answers the above-mentioned problems, and especially the second, showing that it pertains to the consideration of the same natural science to consider both form and matter. For the first question seems to have been adequately answered by what he has said, namely, that the consideration of natural science is the same as the consideration of what the snub is.
Concerning this, therefore, he makes two points.
First, he states what the ancients seem to have thought. He says that, if one wishes to look at the sayings of the ancient natural philosophers, it seems that, for them, natural science is concerned only with matter. For they said either nothing about form, or some small bit, as when Democritus and Empedocles touched upon it insofar as they held that a thing comes to be from many according to a determinate mode of mixing or joining.
170. Second, at “but if on the other hand” (194a21), he proves his position with three arguments.
The first of these is as follows. Art imitates nature. Therefore, natural science must be related to natural things as the science of the artificial is related to artificial things. But it belongs to the same science of the artificial to know the matter and the form up to a certain point, as the doctor knows health as a form and bile and phlegm and such things as the matter in which health is. For health consists in a harmony of humors. And, in like manner, the builder considers the form of the house and also the bricks and the wood that are the matter of the house. And so it is in all the other arts. Therefore, it belongs to the same natural science to know both the matter and the form.
171. The reason for saying that art imitates nature is as follows. Knowledge is the principle of operation in art. But all of our knowledge is through the senses and taken from sensible, natural things. Hence, in artificial things, we work to a likeness of natural things. And so, imitable natural things are produced through art, because all nature is ordered to its end by some intellective principle, such that the work of nature thus seems to be the work of intelligence as it proceeds to certain ends through determinate means. And this order is imitated by art in its operation.
172. He gives the second argument at again, “that for the sake of which” (194a27). It belongs to the same science to consider the end and those things that are for the end. This is so because the reason for those things that are for the end is taken from the end.
But nature, which is form, is the end of matter. Therefore, it belongs to the same natural science to consider matter and form.
173. That form is the end of matter he proves as follows. In order for something to be the end of a continuous motion, two things are required.
First, it must be the final stage of the motion;
second, it must be that for the sake of which the thing comes to be.
For something can be last but not be that for the sake of which something comes to be, and hence not have the account of an end.
And, because it is in the account of an end that it be that for the sake of which something comes to be, the poet maintained that it would be a jest to say that he has the end for the sake of which he was born.
This seemed to him to be a trifle, for just as if we were to say man animal because animal is in the account of man, so also that for the sake of which something comes to be is in the account of end.
For the poet wished to say that not every last thing is an end, but rather only that which is last and best. This is that for the sake of which something comes to be.
And, indeed, that the form is last in generation is per se evident. But that it is that for the sake of which something comes to be with respect to matter is made clear by a simile taken from the arts. Certain arts make matter, and of these, some make it simply (as the art of the potter makes tiles that are the matter of a house), while others make it operative, that is, they dispose matter preexisting in nature for the reception of a form (as the art of the carpenter prepares wood for the form of a ship). It must further be noted that we use all things that are made by art as though they exist for us. For we are, in a sense, the end of all artificial things. And he says in a sense because, as is said in first philosophy, that for the sake of which something comes to be is used in two ways: “of which” and “for which.” Thus, the end of a house as “of which” is the dweller, as “for which” it is a dwelling.
From this, therefore, we can conclude that there are two arts that govern the matter and have knowledge, that is, those that direct the arts that make matter and those that pass judgment on the former.
Thus, there is one art that uses and another art that makes the artifact, namely, by inducing the form. And this latter art is architectonic with reference to that which disposes matter.
Thus the art of the ship builder is architectonic with respect to the art of the carpenter who cuts wood. Hence it is necessary that the art that uses be in a sense architectonic, the principal art, with respect to the productive art.
Therefore, although both are architectonic, meaning the art that uses and the productive art, they nevertheless differ. For the art that uses is architectonic insofar as it knows and passes judgment on the form, whereas the other, which is architectonic as productive of the form, knows the matter, that is, passes judgment on the matter.
He makes this clear by an example. The use of a ship pertains to the navigator; thus, the art of the navigator is an art that uses, and hence it is architectonic with respect to the art of the ship builder and knows and passes judgment on the form. He says that the navigator knows and judges what the shape of the rudder should be.
The other art, however—namely, the art of the ship builder—knows and judges from what wood and from what kind of wood the ship should be made. It is clear, therefore, that the art that produces the form directs the art that makes or disposes the matter. However, the art that uses the completed artifact directs the art that produces the form.
From this, then, we can conclude that matter is related to form as form is related to use. But use is that for the sake of which the artifact comes to be. Therefore, form also is that for the sake of which matter is in artificial things. And so, just as in those things that are according to art we make matter for the sake of the work of art, which is the artifact itself, likewise matter is in natural things from nature, and not made by us. Nevertheless, it has the same ordination to form: it is for the sake of form.
Hence, it follows that it belongs to the same natural science to consider the matter and the form.
174. He gives the third argument at “again, matter is” (194b8). The argument is as follows. Things that are related belong to one science. But matter is one of the things that are related, because it is spoken of in relation to form. However, it is not spoken of as if matter itself were in the genus of relation, but rather because a proper matter is determined for each form. And he adds that there must be a different matter under a different form. Hence, it follows that the same natural science considers form and matter.
175. Next, at “how far, then” (194b9), he shows to what extent natural science considers form.
Concerning this, he makes two points.
First, he raises the question of to what extent natural science should consider the form and quiddity of a thing. (For to consider the forms and quiddities of things absolutely seems to belong to first philosophy.)
Second, he answers the question by saying that, as the doctor considers nerves, and the smith considers bronze, up to a certain point, so also the natural philosopher considers forms. For the doctor does not consider nerve insofar as it is nerve, for this belongs to the natural philosopher. Rather, he considers it as a subject of health. So also the smith does not consider bronze insofar as it is bronze, but insofar as it is the subject of a statue or something of the sort.
So also the natural philosopher does not consider form insofar as it is form, but insofar as it is in matter. And thus, as the doctor considers nerve only insofar as it pertains to health, for the sake of which he considers nerve, so also the natural philosopher considers form only insofar as it has existence in matter.
And so, the last things considered by natural science are forms that are, indeed, in some way separated but that have existence in matter. And rational souls are forms of this sort. For such souls are indeed separated, insofar as the intellective power is not the act of a corporeal organ, as the power of seeing is the act of an eye. But they are in matter insofar as they give natural existence to such a body. That such souls are in matter he proves as follows. The form of anything generated from matter is a form that is in matter. For the generation is terminated when the form is in matter. But man is generated from matter and by man, as by a proper agent, and by the sun, as by a universal agent with respect to the generable. Hence, it follows that the soul, which is the human form, is a form in matter. Thus, the consideration of natural science about forms extends to the rational soul.
But how forms are totally separated from matter, and what they are, or even how this form, the rational soul, exists insofar as it is separable and capable of existence without a body, and what it is according to its separable essence, are questions that pertain to first philosophy.