LECTURE 10 (213 b 30-214 b 11)

WHAT THE WORD 'VOID' MEANS. THE ARGUMENTS OF THOSE WHO POSIT A VOID ARE REFUTED

             506. The Philosopher has said above that we must begin with three things. Therefore, after he has treated two of these, that is, the opinions of those who affirm and of those who deny that a void exists, he here takes up the third point, that is, the common opinions of men concerning the void.

             Concerning this he makes three points. First he explains what the word 'void' means. Secondly, where he says, 'Since we have determined . . .' (214 a 17), he shows how some have held that there is a void. Thirdly, where he says, 'But there is no necessity . . .' (214 a 26), he refutes the arguments of those who hold that there is a void.

             Concerning the first part he makes two points. First he states his intention, and secondly he carries it out, where he says, 'The void is thought . . .' (213 b 32).

             507. He says, therefore, first that since some, as was said, have held that a void exists and some have denied it, in order to know the truth it is necessary to establish as a beginning what the word 'void' means. For when it is asked whether some passion is present in a subject, it is necessary to establish what the thing is for a beginning. In like manner when it is asked whether something is, it is necessary to establish what the word means for a middle term. For the question of what a thing is is subsequent to the question of whether it is.

             508. Next where he says, 'The void is thought . . .' (213 b 32), he explains what the word 'void' means. First he gives the more common meaning. Secondly, where he says, 'In another way . . .' (214 a 12), he gives the meaning used by the Platonists.

             Concerning the first part he makes three points. First he explains what the word 'void' means. Secondly, where he says, 'It would be absurd . . .' (214 a 5), he explains what must be added to this meaning. Thirdly, where he says, 'So we would raise . . .' (214 a 9), he answers a certain difficulty.

             509. He says, therefore, first that according to the opinion of men 'void' seems to mean nothing else than a place in which there is nothing. The reason for this is that a void is properly said to be that in which there is no body. For being in place belongs only to a body, and 'void' can mean nothing else than a place without something located in it. But since men think that every being is a body, it follows according to their opinion that where there is no body there is nothing.

             Further they think that every body is tangible, that is, that it has tangible qualities. A body of this kind is heavy or light. For it was not yet known that a celestial body is beyond the nature of the four elements. Hence since the proper nature [ratio] of a void is that it is a place in which there is no body, it follows that a void is that in which there is no light nor heavy body. This, indeed, is not the nature [ratio] of a void according to the first use of the word, but according to a certain syllogistic deduction from the common opinion of men, who think that every body is light or heavy. Likewise according to the common opinion of men, who think that every being is a body, it follows that a void is that in which there is nothing.

             Therefore, the meaning of this word can be taken in three ways. First and properly a void is a place in which there is no body. The other two meanings are according to the opinion of men. The first of these is more common--a void is a place in which there is nothing. The other is more limited--a void is a place in which there is no light or heavy body.

             510. Next where he says, 'It would be absurd . . .' (214 a 5), he explains what must be added to this meaning. He says that it is unsuitable to say that a point is a void since it can be said that there is no tangible body in a point. Therefore, we must add that a void is a place in which there is no tangible body, but there is there a space susceptible of a tangible body; as that which lacks sight but should have it is called blind. Thus he concludes that in one way a void is said to be a space which is not filled by a tangible body, that is, by a body that is light or heavy.

             511. Next where he says, 'So we would raise . . .' (214 a 9), he answers a certain difficulty. The problem is whether or not there is a void in a space in which there is colour or sound. This difficulty arises because of the definition given first--that is, a void is that in which there is nothing. He answers this by saying that if a space in which there is only sound or colour is susceptive of a tangible body, then it is a void. And if not, it is not a void. This is so because the proper definition of a void is not 'that in which there is nothing', except according to the opinion of those who believe that where there is no body there is nothing.

             512. Next where he says, 'In another way . . .' (214 a 12), he gives another meaning of 'void' as used by the Platonists.

             He says that in another meaning a void is said to be that in which there is not 'a this' or any corporeal substance. But 'a this' comes to be through the form. Hence some say that the matter of a body, insofar as it is without form, is a void. They also say that matter is place, as was said above. But they do not speak well, for matter is not separable from the things of which it is the matter. Men, however, seek place and the void as something separable from located bodies.

             513. Next where he says, 'Since we have determined . . .' (214 a 17), he shows how some have held that there is a void. First he explains what they say a void is. Secondly, where he says, 'For the fact of motion . . .' (214 a 22), he explains why they posit a void.

             He says, therefore, first that a void is a place deprived of body. Now it has been determined in what way place is and in what way it is not (for it was said that place is not space, but the terminus of the container). Hence it is also clear that a void is not a space either separated from bodies or intrinsic to bodies, as Democritus held. This is so because those who posit a void in either of these ways wish to say that a void is not a body, but the space of a body. Therefore a void seems to be something because place is something. And as place seems to be space, so does a void. Hence if place is not a space beyond bodies, then neither can a void be a space beyond bodies. And since the nature [ratio] of a void is that it is a space of a body beyond bodies, as was said above, it follows that a void does not exist.

             514. Next where he says, 'For the fact of motion . . .' (214 a 22), he explains why they posit a void.

             He says that they accept the existence of a void for the same reason that they accept the existence of place, that is, because of motion, as was said above. This is done so that motion in respect to place may be saved, both by those who say that place is something beyond the bodies which are in place and by those who hold that a void exists. But for those who deny place and a void, motion in respect to place does not occur. Thus they think that a void is a cause of motion in the way in which place is; namely, as that in which there is motion.

             515. Next where he says, 'But there is no necessity . . .' (214 a 26), he refutes the arguments of those who hold that a void exists. He does not intend here to give the true solution of the arguments given above, but to give for the present a solution from which it appears that these arguments do not conclude of necessity.

             First, therefore, he refutes the arguments of those who hold a separated void, and secondly, where he says, 'And things can also be . . .' (214 a 33), the arguments of those who hold that there is a void in bodies.

             516. He refutes the first position in two ways. First if there is motion, it is not necessary that there is a void. If we speak universally of every species of motion, it is quite apparent that there is no necessity. For nothing prevents a plenum from being changed in quality. Only local motion seems to be excluded if there is no void. Melissus failed to see this when he believed that, if a void is denied, then every species of motion is destroyed.

             Secondly he refutes the same position by showing that even local motion is not destroyed if there is no void.

             For granting that there is no separable space beyond bodies which are moved, there can be local motion in that bodies enter under each other by way of condensation. And thus a thing is moved in a plenum and not in a void.

             This is quite apparent in the generation of continuous bodies, and especially in liquids, as is seen in water. For if a stone is thrown into a large expanse of water, it is clear that certain circles develop around the place of percussion as long as one part of the disturbed water moves another and replaces it. Hence since a smaller part of water enters into a larger part of water by a certain diffusion, the above mentioned circles proceed from small to large until they are totally dissipated.

             517. Next where he says, 'And things can also be . . .' (214 a 33), he refutes the arguments of those who hold that there is a void in bodies.

             The first argument deals with condensation. He says that bodies are condensed and parts of a body enter into each other, not because the entering parts enter into a void place, but because there are holes filled with a more subtle body which is squeezed out by the condensation. Thus when water comes together and is compressed, the air which was in it is removed. This is especially clear in sponges and in other such porous bodies. However this answer does not explain the cause of condensation, which he gives below. Rather it shows that in this way the necessity of a void can be clearly refuted.

             518. Secondly where he says, '. . . and things can increase . . .' (214 b 1), he refutes the argument which deals with increase.

             He says that increase occurs not only through the addition of some body entering into the increased body, so that it is thus necessary that there be a void, but also through alteration. Thus when air comes to be from water, the quantity of the air is larger than the quantity of the water. Indeed this is not the true solution of the above argument, but only some remarks for the present, lest it be necessary to posit a void.

             However the true solution is given in De Generatione et Corruptione, where it is shown that nourishment is not brought into that which grows as a body distinct from itself, but as converted into its substance, as when wood that is near to fire is converted into fire.

             519. Thirdly where he says, 'In general, both the argument . . .' (214 b 3), he refutes both the argument about increase and the argument about water poured into ashes. He says that each of these arguments is self-destructive. This is clear as follows.

             There is this difficulty about the argument. It seems either that the whole is not increased, or that the increase does not occur because of the addition of a body, but because of the addition of something incorporeal, or that it happens that two bodies are in the same place. Therefore they wish to answer this difficulty which seems to be contrary both to those who posit a void and to those who do not. But they do not demonstrate that there is a void. For it would be necessary for them to say, if increase is due to a void, that the whole body is a void, because the whole body increases.

             The same thing must be said about the ashes. For if a vase filled with ashes receives as much water as a void, then one must say that the whole is a void. Hence this is not due to a void but to the mixture with the water. For water mixed with ashes is condensed and some part of it is emitted. And also the parts of the ashes become more dense by dissolving. A sign of this is that one cannot remove the same amount of water as was formerly there.

             Lastly he concludes that it is clear that it is easy to answer the arguments by which they demonstrate that a void exists.