De Generatione et Corruptione[1]

translated by H. H. Joachim in W. D. Ross, ed., The Works of Aristotle, vol. 2 (Oxford: Oxford, 1930)

http://web.lemoyne.edu/giunta/ea/ARISTOTLEann.HTML

Book II, Chapter 1

We have explained under what conditions "combination," "contact," and "action-passion" are attributable to the things which undergo natural change. Further, we have discussed "unqualified" coming-to-be and passing-away, and explained under what conditions they are predicable, of what subject, and owing to what cause. Similarly, we have also discussed "alteration," and explained what "altering" is and how it differs from coming-to-be and passing-away. But we have still to investigate the so-called "elements" of bodies.

For the complex substances whose formation and maintenance are due to natural processes all presuppose the perceptible bodies as the condition of their coming-to-be and passing-away: but philosophers disagree in regard to the matter which underlies these perceptible bodies.[2] Some maintain it is single, supposing it to be, e.g. Air or Fire, or an "intermediate" between these two (but still a body with a separate existence). Others, on the contrary, postulate two or more materials--ascribing to their "association" and "dissociation," or to their "alteration," the coming-to-be and passing-away of things. (Some, for instance, postulate Fire and Earth: some add Air, making three: and some, like Empedokles, reckon Water as well, thus postulating four.[3])

Now we may agree that the primary materials, whose change (whether it be "association and dissociation" or a process of another kind) results in coming-to-be and passing-away, are rightly described as "originative sources, i.e. elements." But (i) those thinkers are in error who postulate, beside the bodies we have mentioned, a single matter--and that corporeal and separable matter. For this "body" of theirs cannot possibly exist without a "perceptible contrariety": this "Boundless" [apeiron] which some thinkers identify with the "original real," must be either light or heavy, either cold or hot. ^a And (ii) what Plato has written in the Timaeus is not based on any precisely-articulated conception. For he has not stated clearly whether his "Omnirecipient" exists in separation from the "elements"; nor does he make any use of it. He says, indeed, that it is a substratum prior to the so-called "elements"--underlying them, as gold underlies the things that are fashioned of gold. (And yet this comparison, if thus expressed, is itself open to criticism. Things which come-to-be and pass-away cannot be called by the name of the material out of which they have come-to-be: it is only the results of "alteration" which retain the name of the substratum whose "alterations" they are. However, he actually says that "far the truest account is to affirm that each of them is 'gold.'") Nevertheless he carries his analysis of the "elements"--solids though they are--back to "planes," and it is impossible for "the Nurse" (i.e. the primary matter) to be identical with "the planes."^b

Our own doctrine is that although there is a matter of the perceptible bodies (a matter out of which the so-called "elements" come-to-be), it has no separate existence, but is always bound up with a contrariety.[4] A more precise account of these presuppositions has been given in another work[5]: we must, however, give a detailed explanation of the primary bodies as well, since they too are similarly derived from the matter. We must reckon as an "originative source" and as "primary" the matter which underlies, though it is inseparable from, the contrary qualities: for "the hot" is not matter for "the cold" nor "the cold" for "the hot," but the substratum is matter for them both. We therefore have to recognize three "originative sources": firstly that which is potentially perceptible body, secondly the contrarieties (I mean, e.g., heat and cold), and thirdly Fire, Water, and the like. Only "thirdly," however: for these bodies change into one another (they are not immutable as Empedokles and other thinkers assert, since "alteration" would then have been impossible), whereas the contrarieties do not change.

Nevertheless, even so the question remains: What sorts of contrarieties, and how many of them, are to be accounted "originative sources" of body?[6] For all the other thinkers assume and use them without explaining why they are these or why they are just so many.

Book II, Chapter 2

Since, then, we are looking for "originative sources" of perceptible body; and since "perceptible" is equivalent to "tangible," and "tangible" is that of which the perception is touch; it is clear that not all the contrarieties constitute "forms" and "originative sources" of body, but only those which correspond to touch. For it is in accordance with a contrariety--a contrariety, moreover, of tangible qualities--that the primary bodies are differentiated. That is why neither whiteness (and blackness), nor sweetness (and bitterness), nor (similarly) any quality belonging to the other perceptible contrarieties either, constitutes an "element."[7] And yet vision is prior to touch, so that its object also is prior to the object of touch. The object of vision, however, is a quality of tangible body not qua tangible, but qua something else--qua something which may well be naturally prior to the object of touch.

Accordingly, we must segregate the tangible differences and contrarieties, and distinguish which amongst them are primary. Contrarieties correlative to touch are the following: hot-cold, dry-moist, heavy-light, hard-soft, viscous-brittle, rough-smooth, coarse-fine. Of these (i) heavy and light are neither active nor susceptible. Things are not called "heavy" and "light" because they act upon, or suffer action from, other things. But the "elements" must be reciprocally active and susceptible, since they "combine" and are transformed into one another. On the other hand (ii) hot and cold, and dry and moist, are terms, of which the first pair implies power to act and the second pair susceptibility. "Hot" is that which "associates" things of the same kind (for "dissociating," which people attribute to Fire as its function, is "associating" things of the same class, since its effect is to eliminate what is foreign), while "cold" is that which brings together, i.e. "associates," homogeneous and heterogeneous things alike. And moist is that which, being readily adaptable in shape, is not determinable by any limit of its own: while "dry" is that which is readily determinable by its own limit, but not readily adaptable in shape.[8]

[....] It is clear, then, that all the other differences reduce to the first four, but that these admit of no further reduction. For the hot is not essentially moist or dry, nor the moist essentially hot or cold: nor are the cold and the dry derivative forms, either of one another or of the hot and the moist. Hence these must be four.

Book II, Chapter 3

The elementary qualities are four, and any four terms can be combined in six couples. Contraries, however, refuse to be coupled: for it is impossible for the same thing to be hot and cold, or moist and dry.[9] Hence it is evident that the "couplings" of the elementary qualities will be four: hot with dry and moist with hot, and again cold with dry and cold with moist. And these four couples have attached themselves to the apparently "simple" bodies (Fire, Air, Water, and Earth) in a manner consonant with theory. For Fire is hot and dry, whereas Air is hot and moist (Air being a sort of aqueous vapour); and Water is cold and moist, while Earth is cold and dry.[10] Thus the differences are reasonably distributed among the primary bodies, and the number of the latter is consonant with theory. For all who make the simple bodies "elements" postulate either one, or two, or three, or four. Now (i) those who assert there is one only, and then generate everything else by condensation and rarefaction, are in effect making their "originative sources" two, viz. the rare and the dense, or rather the hot and the cold: for it is these which are the moulding forces, while the "one" underlies them as a "matter."[11] But (ii) those who postulate two from the start--as Parmenides postulated Fire and Earth--make the intermediates (e.g. Air and Water) blends of these. The same course is followed (iii) by those who advocate three. (We may compare what Plato does in "The Divisions": for he makes "the middle" a blend.) Indeed, there is practically no difference between those who postulate two and those who postulate three, except that the former split the middle "element" into two, while the latter treat it as only one. But (iv) some advocate four from the start, e.g. Empedokles: yet he too draws them together so as to reduce them to the two, for he opposes all the others to Fire.

In fact, however, fire and air, and each of the bodies we have mentioned, are not simple, but blended. The "simple" bodies are indeed similar in nature to them, but not identical with them. Thus the "simple" body corresponding to fire is "such-as-fire," not fire: that which corresponds to air is "such-as-air:" and so on with the rest of them.[12] But fire is an excess of heat, just as ice is an excess of cold. For freezing and boiling are excesses of heat and cold [sic] respectively. Assuming, therefore, that ice is a freezing of moist and cold, fire analogously will be a boiling of dry and hot: a fact, by the way, which explains why nothing comes-to-be either out of ice or out of fire.[13]

The "simple" bodies, since they are four, fall into two pairs which belong to the two regions, each to each: for Fire and Air are forms of the body moving towards the "limit," while Earth and Water are forms of the body which moves towards the "centre." Fire and Earth, moreover, are extremes and purest: Water and Air, on the contrary are intermediates and more like blends. And, further, the members of either pair are contrary to those of the other, Water being contrary to Fire and Earth to Air; for the qualities constituting Water and Earth are contrary to those that constitute Fire and Air. Nevertheless, since they are four, each of them is characterized par excellence a single quality: Earth by dry rather than by cold, Water by cold rather than by moist, Air by moist rather than by hot, and Fire by hot rather than by dry.

Book II, Chapter 4

It has been established before that the coming-to-be of the "simple" bodies is reciprocal. At the same time, it is manifest, even on the evidence of perception, that they do come-to-be: for otherwise there would not have been "alteration," since "alteration" is change in respect to the qualities of the objects of touch. Consequently, we must explain (i) what is the manner of their reciprocal transformation, and (ii) whether every one of them can come-to-be out of every one--or whether some can do so, but not others.

Now it is evident that all of them are by nature such as to change into one another: for coming-to-be is a change into contraries and out of contraries, and the "elements" all involve a contrariety in their mutual relations because their distinctive qualities are contrary. For in some of them both qualities are contrary--e.g. in Fire and Water, the first of these being dry and hot, and the second moist and cold: while in others one of the qualities (though only one) is contrary--e.g. in Air and Water, the first being moist and hot, and the second moist and cold. It is evident, therefore, if we consider them in general, that every one is by nature such as to come-to-be out of every one: and when we come to consider them severally, it is not difficult to see the manner in which their transformation is effected. For, though all will result from all, both the speed and the facility of their conversion will differ in degree.[14]

Thus (i) the process of conversion will be quick between those which have interchangeable "complementary factors," but slow between those which have none. The reason is that it is easier for a single thing to change than for many. Air, e.g., will result from Fire if a single quality changes: for Fire, as we saw, is hot and dry while Air is hot and moist, so that there will be Air if the dry be overcome by the moist. Again, Water will result from Air if the hot be overcome by the cold: for Air, as we saw, is hot and moist while Water is cold and moist, so that, if the hot changes, there will be Water. So too, in the same manner, Earth will result from Water and Fire from Earth, since the two "elements" in both these couples have interchangeable "complementary factors." For Water is moist and cold while Earth is cold and dry--so that, if the moist be overcome, there will be Earth: and again, since Fire is dry and hot while Earth is cold and dry, Fire will result from Earth if the cold pass-away.

It is evident, therefore, that the coming-to-be of the "simple" bodies will be cyclical; and that this cyclical method of transformation is the easiest, because the consecutive "elements" contain interchangeable "complementary factors."[15] On the other hand (ii) the transformation of Fire into Water and of Air into Earth, and again of Water and Earth into Fire and Air respectively, though possible, is more difficult because it involves the change of more qualities. For if Fire is to result from Water, both the cold and the moist must pass-away: and again, both the cold and the dry must pass-away if Air is to result from Earth. So, too, if Water and Earth are to result from Fire and Air respectively--both qualities must change. [....]

Endnotes

[1]Traditionally, Aristotle's writings are refered to by Latin titles. In English, this work is usually called On Generation and Corruption. The translator uses the somewhat cumbersome terms coming-to-be and passing-away rather than generation and corruption to give a clearer idea of the subject of the treatise.

[2]What is the fundamental material which underlies the substances we can see and feel? What is its nature? Is there only one such primary material, or more than one? These are the questions to which Aristotle now turns.

[3]Empedokles (or Empedocles, c.484-c.424 BCE) accounted for real change by positing that there must be more than one kind of matter: perceptible change is the result of essentially different materials coming together or falling apart in different proportions or arrangements. In particular, he believed in four elements: earth, air, fire, and water. Empedocles was a physician as well as a philosopher. One legend, elaborated by Matthew Arnold, holds that he ended his life by leaping into the crater of Sicily's Mt. Etna.

[4]For Aristotle, the "elements" are not fundamental matter. He believes in the existence of a primary material which is a substrate for qualities ("contrarieties") such as cold and hot, but is inseparable from those qualities. Simple perceptible bodies ("elements") underlie complex perceptible bodies, but the substrate and its qualities underlie the elements. The elements themselves can be changed into one another, but not the qualities.

[5]According to the translator, that other work is Aristotle's Physics, Book I, 6-9. He maintains that the primary matter and contrarieties are accurately defined there. I find there a discussion of contrarieties, but no clear definition of the primary matter. According to Mary Louise Gill, many scholars would not locate a discussion of the primary matter there. Indeed, Gill argues that Aristotle was not committed to a primary matter. [Gill 1989, p. 244] Traditional interpretations of Aristotle hold that he did believe in a primary matter, though, and point to this passage (in Generation and Corruption) as evidence.

[6]The next section, then, will look for those sets of opposing qualities (contrarieties) by which the elements may be differentiated.

[7]First Aristotle equates perceptible with tangible, which is objectionable because there are other modes of perception other than touch. Then he excludes from consideration qualities of perception other than touch. Speaking without any particular insight into Aristotelian dialectic or rhetorical subtleties, I can only regard this passage as unconvincing at best, illogical at worst.

[8]Having narrowed the search to tangible qualities, Aristotle selects two pairs of qualities, the active qualities hot and cold, and the susceptible qualities moist and dry. Then he goes on to relate several other pairs of tangible qualities to moist and dry.

This chapter serves to illustrate the style of Aristotle's discourse. It is deductive (or attempts to be), drawing consequences from principles and definitions. Sometimes the principles are introduced just before they are invoked (as in introducing the principles that the elementary qualities must be active or passive just before using that principle to exclude heavy and light). This in itself makes the argument unconvincing to a modern reader, making it sound like the writer made up the principles as he went along. At least as important for the reader interested in scientific discourse, note that this discourse is general and abstract: there is no reference to empirical observations or even to generalizations from empirical observation.

[9]Given four qualities, how many elements can be formed from two qualities inhering in a substrate? If no restrictions were placed on coupling the qualities, the answer would be six, for there are six ways to select two entities from a group of four. In practice, though, there are restrictions: an element cannot be both hot and cold, nor can one by both wet and dry. Rejecting these two combinations leaves four elements.

[10]Thus the four elements are embodiments of pairs of qualities, as depiected below.

View a more artistic rendering of the four elements, Four elements, seasons and Zodiac. Miniature from English medieval manuscript.

[11]Some ancient Greek philosophers believed there was a single element, but Aristotle seems to say here that even if there existed a single primary matter, the forces which acted on it or the qualities which informed it would have to be plural--at least a pair of contrary qualities--to be able to give rise to observed differences. The substrate itself cannot be an element (simple body), for it cannot exist apart from its qualities; and if there are at least two qualities, there must be at least two combinations of qualities with the substrate.

[12]Aristotle appears to be saying that the elements which are embodiments of qualities are not identical to the physical objects which go by the same name. For instance, the element air ("such-as-air," as the translator renders it) is not quite the same thing as the material one feels on a windy day.

[13]This statement appears to be scientific in that it purports to be an explanation of a generalized observation. Forget, for a moment, that there really is no explanation in the statement. (How does the ice being a freezing of moist and cold "explain" the alleged fact that nothing comes to be from ice?) The observation which is supposedly explained was not arrived at by scientific means. No data lie behind it--certainly no controlled data.

[14]No one of Aristotle's elements is more fundamental than another; indeed, they can be transformed one into another. They have irreducible differences but enough similarity to make transformation possible. The modern understanding of protons and neutrons in β radioactive decay is reminiscent of this kind of relationship. A proton is neither more nor less fundamental than a neutron, and a neutron does not "contain" a proton. Yet in β decay, a neutron is transformed into a proton, an electron , and an antineutrino.

[15]The translation notes here: "Aristotle has shown that, by the conversion of a single quality in each case, Fire is transformed into Air, Air into Water, Water in to Earth, and Earth into Fire. This is a cycle of transformations. Moreover, the 'elements' have been taken in their natural consecutive series, according to their order in the Cosmos." The cycle, however, can begin with any of the four elements, and proceed either in the direction illustrated or in the opposite direction.