But what time is, and what is its nature, from what has been delivered, is similarly immanifest with the things which we have before discussed: for some say that it is the motion of the universe; but others, that it is the sphere itself. A part, however, of the revolution of the universe is a certain time; but it is not a revolution: for that which is assumed is a part of the revolution, and not the revolution. Again, if there were many heavens time would be similarly the motion of any one of these. So that there would be many times subsisting together. But the sphere of the universe seemed to those who made that assertion to be time, because all things are in time and in the sphere of the universe. This assertion, however, is so stupid that it is not requisite to consider the impossibilities with which it is attended. But since time especially appears to be motion and mutation, this must be considered. The mutation therefore, and motion of every thing, is in that alone which is changed, or wherever that may be which is moved and changed. But time is similarly every where, and with all things. Besides, every mutation is swifter and slower; but time is not: for the slow and the swift are defined by time; since that is swift which is much moved in a short time; and that is slow whieh is but a little moved in a long time. But time is not defined by time, neither because it is a certain quantity, nor because it is a certain quality. It is evident, therefore, that time is not motion. But there is no difference whether at present we say it is not motion, or that it is not mutation.
