Lecture 2 — The basic reason for these differing opinions on generation and alteration.

Those, then, who construct all things out of a single element, must maintain that coming-to-be and passing-away are 'alteration'. For they must affirm that the underlying something always remains identical and one; and change of such a substratum is what we call 'altering'.

Those, on the other hand, who make the ultimate kinds of things more than one, must maintain that 'alteration' is distinct from coming-to-be: for coming-to-be and passing-away result from the consilience and the dissolution of the many kinds. That is why Empedocles too uses language to this effect, when he says there is no coming-to-be of anything, but only a mingling and a divorce of what has been mingled. Thus it is clear that to describe coming-to-be and passing-away in these terms is in accordance with their fundamental assumption, and that they do in fact so describe them:

nevertheless, they too must recognize 'alteration' as a fact distinct from coming to-be, though it is impossible for them to do so consistently with what they say. That we are right in this criticism is easy to perceive.

For alteration is a fact of observation. While the substance of the thing remains unchanged, we see it 'altering' just as we see in it the changes of magnitude called 'growth' and 'diminution'. Nevertheless, the statements of those who posit more 'original reals' than one make 'alteration' impossible. For 'alteration, as we assert, takes place in respect to certain qualities: and these qualities (I mean, e.g. hot-cold, white-black, dry-moist, soft-hard, and so forth) are, all of them, differences characterizing the 'elements'. The actual words of Empedocles may be quoted in illustration:

the sun everywhere bright to see, and hot,

the rain everywhere dark and cold.

And he distinctively characterizes his remaining elements in a similar manner. Since, therefore, it is not possible for Fire to become Water, or Water to become Earth, neither will it be possible for anything white to become black, or anything soft to become hard; and the same argument applies to all the other qualities. Yet this is what 'alteration' essentially is.

It follows, as an obvious corollary, that a single matter must always be assumed as underlying the contrary 'poles' of any change whether change of place, or growth and diminution, or 'alteration'; further, that the being of this matter and the being of 'alteration' stand and fall together. For if the change is 'alteration', then the substratum is a single element; i.e. all things which admit of change into one another have a single matter. And, conversely, if the substratum of the changing things is one, there is 'alteration'.

Empedocles, indeed, seems to contradict his own statements as well as the observed facts. For he denies that any one of his elements comes-to-be out of any other, insisting on the contrary that they are the things out of which everything else comes-to-be; and yet (having brought the entirety of existing things, except Strife, together into one) he maintains, simultaneously with this denial, that each thing once more comes-to-be out of the One. Hence it was clearly out of a One that this came-to-be Water, and that Fire, various portions of it being separated off by certain characteristic differences or qualities—as indeed he calls the sun 'white and hot', and the earth 'heavy and hard'. If, therefore, these characteristic differences be taken away (for they can be taken away, since they came-to-be), it will clearly be inevitable for Earth to come to-be out of Water and Water out of Earth, and for each of the other elements to undergo a similar transformation—not only then, but also now—if, and because, they change their qualities. And, to judge by what he says, the qualities are such that they can be 'attached' to things and can again be 'separated' from them, especially since Strife and Love are still fighting with one another for the mastery. It was owing to this same conflict that the elements were generated from a One at the former period. I say 'generated', for presumably Fire, Earth, and Water had no distinctive existence at all while merged in one.

There is another obscurity in the theory Empedocles. Are we to regard the One as his 'original real'? Or is it the Many—i.e. Fire and Earth, and the bodies co-ordinate with these? For the One is an 'element' in so far as it underlies the process as matter—as that out of which Earth and Fire come-to-be through a change of qualities due to 'the motion'. On the other hand, in so far as the One results from composition (by a consilience of the Many), whereas they result from disintegration, the Many are more 'elementary' than the One, and prior to it in their nature.

11. In the preceding lecture Aristotle stated that the reason some ancient philosophers posited generation as differing from alteration, and others did not, was that some postulated one material principle and others more than one. He clarified above the root of this reason, showing how some posited many principles—for in the case of those proposing one principle, the exposition is more unqualified. Now he intends to elucidate this reason in itself. Concerning this he does two things:

first, he manifests the reason;

second, he objects to it, at for alteration is a fact (314b13; [14]).

About the first he does two things:

first, he elucidates the aforesaid reason as to those who posit one principle;

second, as to those who posit several principles, at nevertheless, they too must recognize (314b10; [14]).

12. He says therefore first (314a29) that all the philosophers who assert that all things are produced from one material principle are forced to say that generation and corruption are the same as alteration. For they posited their one material principle to be some actual being, such as fire or air or water; they also posited it to be the substance of all things generated from it. And just as the matter always persists in things made from matter, so they said, that this subject remains one and the same. Now we say that a thing is altered when, with the substance of the thing in act remaining, some variation occurs with respect to the form. Hence it follows that there can be no change called simple generation and corruption, but only alteration.

We, on the other hand, declare that there is of all generable and corruptible things one first subject, which, however, is not a being in act but in potency. Therefore when its first subject acquires a form through which it becomes a being in act, this is called simple generation. But it is said to be altered when, after being made a being in act, it acquires any additional form.

13. Then, at those, on the other hand (314b3), he elucidates the aforesaid reason as to those who posited several principles. And he says that those, mentioned above, who assign many kinds of material principles, must say that generation differs from alteration. For according to those philosophers, generation comes about when those material principles combine into one; when they are separated, corruption occurs. Hence Empedocles asserts that the "nature," i.e., the form, of a body composed of elements is none of the elements (for it is not of the nature of fire or of water or of the other elements), but it is solely a "mixture," i.e., it consists solely in a certain "mixed" nature, and the opposite privation consists in the separation of what was mixed. And since something is said to be generated when it acquires its appropriate nature, they posited that generation resulted from aggregation, and corruption from separation. But alteration, they said, takes place only through transmutation, as will be explained later. Therefore, since this explanation fits their supposition, and they do indeed speak thus, it is plain that they so speak of the difference between generation and alteration, as has been said.

14. Then, at nevertheless, they too must recognize (314b10) he disproves what has been stated, with respect to those who posit several principles, for those who posit but one principle reach the conclusion with necessity once its root is supposed. Concerning this he does two things:

first, he objects against all of them at once;

second, he objects against Empedocles in particular, at Empedocles, indeed (315a3; [16]).

Concerning the first he does two things.

First, he proposes what he intends, and says that those who posit many principles must admit that generation is different from alteration, as has been said. Nevertheless, this is impossible to maintain in consistency with what they say, as will easily be seen from what follows.

Second, at for alteration is a fact (314b13), he elucidates his proposition with two arguments.

In regard to the first, he presents an analogy and says that, just as, while the substance "rests," i.e., remains, we see a change occur in it as to size, called "growth" and "decrease," so too with alteration, which is a motion according to quality. For just as quantity is based on substance, so too is quality. But according to what is posited by those philosophers who assume many principles, it is impossible for alteration to occur in this manner. For they say that the "passions," i.e., the passible qualities, with respect to which we state this, namely, alteration to occur, are the proper differences of the elements, namely, hot and cold, white and black, dry and moist, soft and hard, and so on. For example, Empedocles stated that the "sun," i.e., fire, since he posited the sun to be of the nature of fire, is seen as white and hot; "rain," i.e., water, is seen always as dark, cold and cloudy, as is evident from the darkening of the air when it rains. He explained the other passions in a similar way, attributing them to the elements.

They said that it was not possible for water to be produced from fire, or earth from water, or for any one of the elements to be converted into another in any way whatsoever. For they did not posit such elements as composed of matter and form, so that out of the corruption of one, another could be generated. Rather they posited them as first matters that would not be resolved into some first subject. But whatever is to be converted into something else must be resolved into some first subject. Now it is impossible for the proper accidents of a thing to be anywhere but in their proper subject. Hence, if "hot" is the proper accident of fire, and "cold" of water, "hot" can be found only in fire and "cold" only in water, and so on for the others. If, therefore, fire cannot come to be from water, nor one element from another, then black cannot come to be from white or hard from soft. And the same goes for all other such qualities. Consequently, since alteration occurs only when one or another of these qualities varies in one and the same subject, there is no such thing as alteration. Therefore they have no grounds to posit a difference between generation and alteration.

15. He presents the second argument at it follows, as an obvious corollary (314b26) and says that it is necessary in any motion to suppose one nature for the contraries which are the termini of the motion, namely, whether something is being transmuted with respect to place, or growth and decrease. Likewise, this must be so in alteration, namely, that if there is alteration, there be one subject and one matter for all the things having such a mutual change, and that if those have one subject when alteration is looked for, it follows that there be alteration. But since the aforesaid thinkers do not posit one subject for all the qualities involved in alteration, but several, they cannot posit alteration. Consequently, they groundlessly say alteration to be different from generation.

This argument differs from the first in that it states the universal cause of the middle term used in the first one.

16. Then, at Empedocles, indeed (315a3), he disputes against Empedocles in particular, with two arguments.

In the first of these he declares that Empedocles seems to be at odds not only with what our senses reveal, namely, the fact that we see that air comes to be from water and fire from air, but he seems to contradict himself also. For, on the one hand, he says that no element is generated from another, but all other "elemented" bodies are composed of them; and, on the other hand, he says that before this present world was generated, all the nature of things was assembled by Friendship into one, minus Strife, and that each of the elements and also each of the other bodies came to be out of that one through the influence of Strife, separating things. From this it is plain that through certain differences and passions of the various elements it was brought about by Strife out of that one that one thing be water and another fire.

And he gives an example of the "differences and passions"—thus he [Empedocles] says that the "sun," i.e., fire, is white and hot and light, but earth is heavy and hard. From this, it is evident that such differences are newly acquired by the elements. Now whatever is newly acquired can be removed. Therefore, since these differences are removable inasmuch as they are newly engendered, it is plain that, once removed, it is necessary that water be made from earth, and earth from water, and, in general, each element from some other—and this not only "then," i.e., in the beginning of the world, but also now, coming about through the change of the passions. That such a transmutation of passions can occur he proves in two ways.

First, from the very nature of these passions. For, from what Empedocles says, it follows that they can be newly acquired, for example, when Strife separates, and then be separated from the elements when Friendship unites. He proves it in another way from the cause of those passions, because even now [their causes, namely] Friendship and Strife, are contrary to one another. And therefore then, i.e., in the beginning of the world, the elements were generated from the one, with the differences being acquired, for it cannot be said that fire, earth and water, as actual existents, could constitute the one whole.

17. In the second argument, at there is another obscurity (315a19), he says that it is not certain whether Empedocles should have posited one principle or many, even though he did indeed posit many, namely, fire and earth and other things that co-exist with them. He says it is uncertain because, in so far as there is supposed some one thing out of which, as from matter, fire and earth and water come to be through some transmutation caused by the separating action of Strife, it seems that there is one element. But in so far as that one results from the composition of the elements coming together into one through Friendship, and they, namely, the elements, come to be from that one through a certain dissolving caused by Strife, it seems rather that those four are elements and are prior by nature. And although this was more the idea of Empedocles, positing things as produced through Friendship and Strife, Aristotle nevertheless proves in the preceding argument the elements to be produced not by separation alone, but also by a certain change with the arrival of the differences of the elements. From this follows the contrary to what Empedocles intended; namely, that the one is more of a principle [than they].