not rightly blamed in these things? for the aquatic does not signify the being in something or some where, but a certain quality, since it would be similarly aquatic, if it should even be in a dry place; likewise, also, the terrestrial, even in a moist place, will be terrestrial and not aquatic; at the same time, if ever difference signifies the being in a certain thing, it is evident that (he who defines) will err.
Again, (notice) whether passion is assigned as difference; for every passion, when increased, alters the essence, but difference is not a thing of this kind, but difference appears rather to preserve that of which it is the difference, and it is simply impossible for any thing to be without its proper difference, since pedestrian not existing, there will not be man. In a word, nothing of those, according to which the thing possessing it, is changed in quality, is the difference of it, for all such, when increased, alter the essence, so that if any one assigns a certain difference of this kind, he errs, as, in short, we are not changed in quality, according to differences.
He also (mistakes), who assigns the difference of a certain relative, not with reference to something else; for of relatives, the difference is also a relative, as in the case of science, for it is said to be contemplative, practical, and effective; but each of these signifies relation, since it is contemplative of something, and effective, and practical of something.
Examine, also, whether he who defines, assigns that to which each relative is naturally adapted, for some things can only be employed for that to which each relative is naturally adapted, but for nothing else, some, on the other hand, for something else also; thus, the sight is (employed) for seeing only, but some one may draw up a weight, even with a strigil; notwithstanding, whoever should define a strigil an instrument for drawing would err, for it is not naturally adapted to this; the definition however of what a thing is naturally adapted to, is that for which a prudent man, so far as he is prudent, would use it, also the science which properly belongs to each.
