by Aristotle
   everything else (for there will be no flesh in the remaining water);
   if on the other hand it does not, and further extraction is always
   possible, there will be an infinite multitude of finite equal
   particles in a finite quantity-which is impossible. Another proof
   may be added: Since every body must diminish in size when something is
   taken from it, and flesh is quantitatively definite in respect both of
   greatness and smallness, it is clear that from the minimum quantity of
   flesh no body can be separated out; for the flesh left would be less
   than the minimum of flesh.
   Lastly (4) in each of his infinite bodies there would be already
   present infinite flesh and blood and brain- having a distinct
   existence, however, from one another, and no less real than the
   infinite bodies, and each infinite: which is contrary to reason.
   The statement that complete separation never will take place is
   correct enough, though Anaxagoras is not fully aware of what it means.
   For affections are indeed inseparable. If then colours and states
   had entered into the mixture, and if separation took place, there
   would be a 'white' or a 'healthy' which was nothing but white or
   healthy, i.e. was not the predicate of a subject. So his 'Mind' is
   an absurd person aiming at the impossible, if he is supposed to wish
   to separate them, and it is impossible to do so, both in respect of
   quantity and of quality- of quantity, because there is no minimum
   magnitude, and of quality, because affections are inseparable.
   Nor is Anaxagoras right about the coming to be of homogeneous
   bodies. It is true there is a sense in which clay is divided into
   pieces of clay, but there is another in which it is not. Water and air
   are, and are generated 'from' each other, but not in the way in
   which bricks come 'from' a house and again a house 'from' bricks;
   and it is better to assume a smaller and finite number of
   principles, as Empedocles does.
   5
   All thinkers then agree in making the contraries principles, both
   those who describe the All as one and unmoved (for even Parmenides
   treats hot and cold as principles under the names of fire and earth)
   and those too who use the rare and the dense. The same is true of
   Democritus also, with his plenum and void, both of which exist, be
   says, the one as being, the other as not-being. Again he speaks of
   differences in position, shape, and order, and these are genera of
   which the species are contraries, namely, of position, above and
   below, before and behind; of shape, angular and angle-less, straight
   and round.
   It is plain then that they all in one way or another identify the
   contraries with the principles. And with good reason. For first
   principles must not be derived from one another nor from anything
   else, while everything has to be derived from them. But these
   conditions are fulfilled by the primary contraries, which are not
   derived from anything else because they are primary, nor from each
   other because they are contraries.
   But we must see how this can be arrived at as a reasoned result,
   as well as in the way just indicated.
   Our first presupposition must be that in nature nothing acts on,
   or is acted on by, any other thing at random, nor may anything come
   from anything else, unless we mean that it does so in virtue of a
   concomitant attribute. For how could 'white' come from 'musical',
   unless 'musical' happened to be an attribute of the not-white or of
   the black? No, 'white' comes from 'not-white'-and not from any
   'not-white', but from black or some intermediate colour. Similarly,
   'musical' comes to be from 'not-musical', but not from any thing other
   than musical, but from 'unmusical' or any intermediate state there may
   be.
   Nor again do things pass into the first chance thing; 'white' does
   not pass into 'musical' (except, it may be, in virtue of a concomitant
   attribute), but into 'not-white'-and not into any chance thing which
   is not white, but into black or an intermediate colour; 'musical'
   passes into 'not-musical'-and not into any chance thing other than
   musical, but into 'unmusical' or any intermediate state there may be.
   The same holds of other things also: even things which are not
   simple but complex follow the same principle, but the opposite state
   has not received a name, so we fail to notice the fact. What is in
   tune must come from what is not in tune, and vice versa; the tuned
   passes into untunedness-and not into any untunedness, but into the
   corresponding opposite. It does not matter whether we take attunement,
   order, or composition for our illustration; the principle is obviously
   the same in all, and in fact applies equally to the production of a
   house, a statue, or any other complex. A house comes from certain
   things in a certain state of separation instead of conjunction, a
   statue (or any other thing that has been shaped) from
   shapelessness-each of these objects being partly order and partly
   composition.
   If then this is true, everything that comes to be or passes away
   from, or passes into, its contrary or an intermediate state. But the
   intermediates are derived from the contraries-colours, for instance,
   from black and white. Everything, therefore, that comes to be by a
   natural process is either a contrary or a product of contraries.
   Up to this point we have practically had most of the other writers
   on the subject with us, as I have said already: for all of them
   identify their elements, and what they call their principles, with the
   contraries, giving no reason indeed for the theory, but contrained
   as it were by the truth itself. They differ, however, from one another
   in that some assume contraries which are more primary, others
   contraries which are less so: some those more knowable in the order of
   explanation, others those more familiar to sense. For some make hot
   and cold, or again moist and dry, the conditions of becoming; while
   others make odd and even, or again Love and Strife; and these differ
   from each other in the way mentioned.
   Hence their principles are in one sense the same, in another
   different; different certainly, as indeed most people think, but the
   same inasmuch as they are analogous; for all are taken from the same
   table of columns, some of the pairs being wider, others narrower in
   extent. In this way then their theories are both the same and
   different, some better, some worse; some, as I have said, take as
   their contraries what is more knowable in the order of explanation,
   others what is more familiar to sense. (The universal is more knowable
   in the order of explanation, the particular in the order of sense: for
   explanation has to do with the universal, sense with the
   particular.) 'The great and the small', for example, belong to the
   former class, 'the dense and the rare' to the latter.
   It is clear then that our principles must be contraries.
   6
   The next question is whether the principles are two or three or more
   in number.
   One they can
not be, for there cannot be one contrary. Nor can they
   be innumerable, because, if so, Being will not be knowable: and in any
   one genus there is only one contrariety, and substance is one genus:
   also a finite number is sufficient, and a finite number, such as the
   principles of Empedocles, is better than an infinite multitude; for
   Empedocles professes to obtain from his principles all that Anaxagoras
   obtains from his innumerable principles. Lastly, some contraries are
   more primary than others, and some arise from others-for example sweet
   and bitter, white and black-whereas the principles must always
   remain principles.
   This will suffice to show that the principles are neither one nor
   innumerable.
   Granted, then, that they are a limited number, it is plausible to
   suppose them more than two. For it is difficult to see how either
   density should be of such a nature as to act in any way on rarity or
   rarity on density. The same is true of any other pair of contraries;
   for Love does not gather Strife together and make things out of it,
   nor does Strife make anything out of Love, but both act on a third
   thing different from both. Some indeed assume more than one such thing
   from which they construct the world of nature.
   Other objections to the view that it is not necessary to assume a
   third principle as a substratum may be added. (1) We do not find
   that the contraries constitute the substance of any thing. But what is
   a first principle ought not to be the predicate of any subject. If
   it were, there would be a principle of the supposed principle: for the
   subject is a principle, and prior presumably to what is predicated
   of it. Again (2) we hold that a substance is not contrary to another
   substance. How then can substance be derived from what are not
   substances? Or how can non-substances be prior to substance?
   If then we accept both the former argument and this one, we must, to
   preserve both, assume a third somewhat as the substratum of the
   contraries, such as is spoken of by those who describe the All as
   one nature-water or fire or what is intermediate between them. What is
   intermediate seems preferable; for fire, earth, air, and water are
   already involved with pairs of contraries. There is, therefore, much
   to be said for those who make the underlying substance different
   from these four; of the rest, the next best choice is air, as
   presenting sensible differences in a less degree than the others;
   and after air, water. All, however, agree in this, that they
   differentiate their One by means of the contraries, such as density
   and rarity and more and less, which may of course be generalized, as
   has already been said into excess and defect. Indeed this doctrine too
   (that the One and excess and defect are the principles of things)
   would appear to be of old standing, though in different forms; for the
   early thinkers made the two the active and the one the passive
   principle, whereas some of the more recent maintain the reverse.
   To suppose then that the elements are three in number would seem,
   from these and similar considerations, a plausible view, as I said
   before. On the other hand, the view that they are more than three in
   number would seem to be untenable.
   For the one substratum is sufficient to be acted on; but if we
   have four contraries, there will be two contrarieties, and we shall
   have to suppose an intermediate nature for each pair separately. If,
   on the other hand, the contrarieties, being two, can generate from
   each other, the second contrariety will be superfluous. Moreover, it
   is impossible that there should be more than one primary
   contrariety. For substance is a single genus of being, so that the
   principles can differ only as prior and posterior, not in genus; in
   a single genus there is always a single contrariety, all the other
   contrarieties in it being held to be reducible to one.
   It is clear then that the number of elements is neither one nor more
   than two or three; but whether two or three is, as I said, a
   question of considerable difficulty.
   7
   We will now give our own account, approaching the question first
   with reference to becoming in its widest sense: for we shall be
   following the natural order of inquiry if we speak first of common
   characteristics, and then investigate the characteristics of special
   cases.
   We say that one thing comes to be from another thing, and one sort
   of thing from another sort of thing, both in the case of simple and of
   complex things. I mean the following. We can say (1) 'man becomes
   musical', (2) what is 'not-musical becomes musical', or (3), the
   'not-musical man becomes a musical man'. Now what becomes in (1) and
   (2)-'man' and 'not musical'-I call simple, and what each
   becomes-'musical'-simple also. But when (3) we say the 'not-musical
   man becomes a musical man', both what becomes and what it becomes
   are complex.
   As regards one of these simple 'things that become' we say not
   only 'this becomes so-and-so', but also 'from being this, comes to
   be so-and-so', as 'from being not-musical comes to be musical'; as
   regards the other we do not say this in all cases, as we do not say
   (1) 'from being a man he came to be musical' but only 'the man
   became musical'.
   When a 'simple' thing is said to become something, in one case (1)
   it survives through the process, in the other (2) it does not. For man
   remains a man and is such even when he becomes musical, whereas what
   is not musical or is unmusical does not continue to exist, either
   simply or combined with the subject.
   These distinctions drawn, one can gather from surveying the
   various cases of becoming in the way we are describing that, as we
   say, there must always be an underlying something, namely that which
   becomes, and that this, though always one numerically, in form at
   least is not one. (By that I mean that it can be described in
   different ways.) For 'to be man' is not the same as 'to be unmusical'.
   One part survives, the other does not: what is not an opposite
   survives (for 'man' survives), but 'not-musical' or 'unmusical' does
   not survive, nor does the compound of the two, namely 'unmusical man'.
   We speak of 'becoming that from this' instead of 'this becoming
   that' more in the case of what does not survive the change-'becoming
   musical from unmusical', not 'from man'-but there are exceptions, as
   we sometimes use the latter form of expression even of what
   survives; we speak of 'a statue coming to be from bronze', not of
   the 'bronze becoming a statue'. The change, however, from an
   opposite which does not survive is described indifferently in both
   ways, 'becoming that from this' or 'this becoming that'. We say both
   that 'the unmusical becomes musical', and that 'from unmusical he
   becomes musical'. And so both forms are used of the complex, 'becoming
   a musical man from an unmusical man', and unmusical man becoming a
   musical man'.
   But there are different senses of 'coming to be'. In some cases we
  
; do not use the expression 'come to be', but 'come to be so-and-so'.
   Only substances are said to 'come to be' in the unqualified sense.
   Now in all cases other than substance it is plain that there must be
   some subject, namely, that which becomes. For we know that when a
   thing comes to be of such a quantity or quality or in such a relation,
   time, or place, a subject is always presupposed, since substance alone
   is not predicated of another subject, but everything else of
   substance.
   But that substances too, and anything else that can be said 'to
   be' without qualification, come to be from some substratum, will
   appear on examination. For we find in every case something that
   underlies from which proceeds that which comes to be; for instance,
   animals and plants from seed.
   Generally things which come to be, come to be in different ways: (1)
   by change of shape, as a statue; (2) by addition, as things which
   grow; (3) by taking away, as the Hermes from the stone; (4) by putting
   together, as a house; (5) by alteration, as things which 'turn' in
   respect of their material substance.
   It is plain that these are all cases of coming to be from a
   substratum.
   Thus, clearly, from what has been said, whatever comes to be is
   always complex. There is, on the one hand, (a) something which comes
   into existence, and again (b) something which becomes that-the
   latter (b) in two senses, either the subject or the opposite. By the
   'opposite' I mean the 'unmusical', by the 'subject' 'man', and
   similarly I call the absence of shape or form or order the 'opposite',
   and the bronze or stone or gold the 'subject'.
   Plainly then, if there are conditions and principles which
   constitute natural objects and from which they primarily are or have
   come to be-have come to be, I mean, what each is said to be in its
   essential nature, not what each is in respect of a concomitant