referred to it; but (3) that which is measured or known or thought is called relative because something else is referred to it. For 'that which is thought' implies that the thought of it exists, but the thought is not relative to 'that of which it is the thought'; for we should then have said the same thing twice. Similarly sight is the sight of something, not 'of that of which it is the sight' (though of course it is true to say this); in fact it is relative to colour or to something else of the sort. But according to the other way of speaking the same thing would be said twice, — 'it is the sight of that which is the object of sight.'
Things that are by their own nature called relative are called so sometimes in these senses, sometimes because the classes that include them are of this sort, e.g. medicine is a relative term because its genus, science, is thought to be a relative term. Further, there are the properties in virtue of which the things that have them are called relative, e.g. equality is relative because the equal is, and likeness because the like is. Other things are relative by accident, e.g. a man is relative because he happens to be double of something and double is a relative term; or the white is relative, if the same thing happens to be double and white.
Chapter 16
'The complete' means (1) that outside which it is not possible to find even one of the parts proper to it, e.g. the complete time of each thing is that outside which it is not possible to find any time which is a part proper to it. — (2) That which in respect of excellence and goodness cannot be excelled in its kind, e.g. a doctor is complete and a flute-player is complete, when they lack nothing in respect of their proper kind of excellence. And thus we transfer the word to bad things, and speak of a complete scandal-monger and a complete thief; indeed we even call them good, i.e. a good thief and a good scandalmonger. And excellence is a completion; for each thing is complete and every substance is complete, when in respect of its proper kind of excellence it lacks no part of its natural magnitude. — (3) The things which have attained a good end
