IX. But to say that time is an appendix of motion, is not to teach what time is, nor ought this to be said before it is shown what the appendix is. For perhaps it may be time. With respect to this appendix, however, it must be considered, whether it has a posterior, or simultaneous, or prior subsistence; if there is an appendix of this kind. For in whatever manner it may be spoken of, it is spoken of in time. Hence, if this is time, it will follow that time is the appendix of motion in time. Since, however, we do not investigate what time is not, but what it is, and much has been said on this subject by many prior to us, according to each position, he who discusses these would rather compose a history (than discover the nature of time). To which may be added, that we have occasionally said something concerning these different positions. Some things also may be opposed from what has been already said, to him who asserts that time is the measure of the universe, and likewise such other things as have just now been asserted respecting the measure of motion. For separate from inequality, all the other particulars may be adduced, which are adapted to their positions. It follows, therefore, that we should now show what it is necessary to think time is.