LESSON 5

Actuality and Its Various Meanings

  Chapter 6: 1048a 25-1048b 36

             768. Since we have dealt with the kind of potency which is related to motion, let us now determine about actuality both what it is and what kind of thing it is. For in making our distinctions it will become evident at the same time with regard to the potential not only that we speak of the potential as that which is disposed by nature to move something else or be moved by something else, either in an unqualified sense or in some special way, but also that we use the word in a different sense as well. And for this reason we will also come upon these points in making our investigations.

             769. Now actuality is the existence of a thing not in the sense in which we say that a thing exists potentially, as when we say that Mercury is potentially in the wood, and a half in the whole, because it can be separated from it, or as we say that one who is not theorizing is a man of science if he is able to theorize; but in the sense in which each of these exists actually.

             770. What we mean becomes evident in particular cases by induction, and we should not look for the boundaries of every thing, but perceive what is proportional; for it is as one who is building to one capable of building, and as one who is awake to one who is asleep, and as one who sees to one whose eyes are closed but who has the power of sight, and as that which is separated out of matter to matter, and as that which has been worked on to that which has not; and let actuality be defined by one member of this division and potency by the other.

             771. However, things are not all said to be actual in the same way, but proportionally, as this is in that or to that; indeed, some are as motion to potency, and others as substance to some matter.

             772. But the infinite and the void and all other such things are said to exist potentially and actually in a different sense from that which applies to many beings, for example, from that which sees or walks or is visible. For these things can be verified, and verified without qualification; for what is visible is so designated sometimes because it is being seen and sometimes because it is capable of being seen. But the infinite does not exist potentially in the sense that it will ever have actual separate existence, but it exists potentially only in knowledge. For since the process of division never comes to an end, this shows that this actuality exists potentially, but not that it ever exists separately. Therefore, regarding actuality, both what it is and what kind of thing it is will be evident to us from these and similar considerations.

COMMENTARY

             1823. Having drawn his conclusions about potency, Aristotle now establishes the truth about actuality; and this is divided into two parts. In the first (768:C 1823) he establishes what actuality is. In the second (773:C 1832) he establishes what is true when something is in potency to actuality ("However, we must").

             In regard to the first he does two things. First, he links this up with the preceding discussion. He says that, since we have dealt with the kind of potency which is found in mobile things, i.e., the kind which is an active or passive principle of motion, we must now explain what actuality is and how it is related to potency; because when we will have distinguished the kinds of actuality, the truth about potency will become evident from this at the same time. For actuality is found not only in mobile things but also in immobile ones.

             1824. And since potency is referred to actuality, it is evident from this that capability or potency taken in reference to action is attributed not only to something that is naturally disposed to move something else actively or be moved by something else passively, either in an unqualified sense, inasmuch as potency is referred alike to acting and being acted upon, or in some special way, inasmuch as potency is referred to what is able to act or be acted upon well; but capability or potency is also referred to that actuality which is devoid of motion. For although the word actuality is derived from motion, as was explained above (758:C 1805), it is still not motion alone that is designated as actuality. Hence, neither is potency referred only to motion. It is therefore necessary to inquire about these things in our investigations.

             1825. Now actuality (769).

             Second, he establishes the truth about actuality. First (769), he shows what actuality is; and second (771:C 1828), how it is used in different senses in the case of different things ("However, things").

             In regard to the first he does two things. First, he shows what actuality is. He says that a thing is actual when it exists but not in the way in which it exists when it is potential. For we say that the image of Mercury is in the wood potentially and not actually before the wood is carved; but once it has been carved the image of Mercury is then said to be in the wood actually. And in the same way we say that any part of a continuous whole is in that whole, because any part (for example, the middle one) is present potentially inasmuch as it is possible for it to be separated from the whole by dividing the whole; but after the whole has been divided, that part will now be present actually. The same thing is true of one who has a science and is not speculating, for he is capable of speculating even though he is not actually doing so; but to be speculating or contemplating is to be in a state of actuality.

             1826. What we mean (770).

             Here he answers an implied question; for someone could ask him to explain what actuality is by giving its definition. And he answers by saying that it is possible to show what we mean (i.e., by actuality) in the case of singular things by proceeding inductively from examples, "and we should not look for the boundaries of everything," i.e., the definition. For simple notions cannot be defined, since an infinite regress in definitions is impossible. But actuality is one of those first simple notions. Hence it cannot be defined.

             1827. And he says that we can see what actuality is by means of the proportion existing between two things. For example, we may take the proportion of one who is building to one capable of building; and of one who is awake to one asleep; and of one who sees to one whose eyes are closed although he has the power of sight; and "of that which is separated out of matter," i.e., what is formed by means of the operation of art or of nature, and thus is separated out of unformed matter, to what is not separated out of unformed matter. And similarly we may take the proportion of what has been prepared to what has not been prepared, or of what has been worked on to what has not been worked on. But in each of these opposed pairs one member will be actual and the other potential. And thus by proceeding from particular cases we can come to an understanding in a proportional way of what actuality and potency are.

             1828. However, things (771).

             Then he shows that the term actuality is used in different senses; and he gives two different senses in which it is used. First, actuality means action, or operation. And with a view to introducing the different senses of actuality he says, first, that we do not say that all things are actual in the same way but in different ones; and this difference can be considered according to different proportions. For a proportion can be taken as meaning that, just as one thing is in another, so a third is in a fourth; for example, just as sight is in the eye, so hearing is in the ear. And the relation of substance (i.e., of form) to matter is taken according to this kind of proportion; for form is said to be in matter.

             1829. There is another meaning of proportion inasmuch as we say that, just as this is related to that, so another thing is related to something else; for example, just as the power of sight is related to the act of seeing, so too the power of hearing is related to the act of hearing. And the relation of motion to motive power or of any operation to an operative potency is taken according to this kind of proportion.

             1830. But the infinite (772).

             Second, he gives the other sense in which the word actuality is used. He says that the infinite and the empty or the void, and all things of this kind, are said to exist potentially and actually in a different sense from many other beings; for example, what sees and what walks and what is visible. For it is fitting that things of this kind should sometimes exist in an unqualified sense either only potentially or only actually; for example, the visible is only actual when it is seen, and it is only potential when it is capable of being seen but is not actually being seen.

             1831. But the infinite is not said to exist potentially in the sense that it may sometimes have separate actual existence alone; but in the case of the infinite, actuality and potentiality are distinguished only in thought and in knowledge. For example, in the case of the infinite in the sense of the infinitely divisible, actuality and potentiality are said to exist at the same time, because the capacity of the infinite for being divided never comes to an end; for when it is actually divided it is still potentially further divisible. However, it is never actually separated from potentiality in such a way that the whole is sometimes actually divided and is incapable of any further division. And the same thing is true of the void; for it is possible for a place to be emptied of a particular body, but not so as to be a complete void, for it continues to be filled by another body; and thus in the void potentiality always continues to be joined to actuality. The same thing is true of motion and time and other things of this kind which do not have complete being. Then at the end he makes a summary of what has been said. This is evident in the text.