But though defining by GENUS and DIFFERENTIA (I crave leave to use these terms of art, though originally Latin, since they most properly suit those notions they are applied to), I say, though defining by the GENUS be the shortest way, yet I think it may be doubted whether it be the best.

This I am sure, it is not the only, and so not absolutely necessary.

For, definition being nothing but making another understand by words what idea the term defined stands for, a definition is best made by enumerating those simple ideas that are combined in the signification of the term defined: and if, instead of such an enumeration, men have accustomed themselves to use the next general term, it has not been out of necessity, or for greater clearness, but for quickness and dispatch sake.

For I think that, to one who desired to know what idea the word MAN stood for; if it should be said, that man was a solid extended substance, having life, sense, spontaneous motion, and the faculty of reasoning, I doubt not but the meaning of the term man would be as well understood, and the idea it stands for be at least as clearly made known, as when it is defined to be a rational animal: which, by the several definitions of ANIMAL, VIVENS, and CORPUS, resolves itself into those enumerated ideas.

I have, in explaining the term MAN, followed here the ordinary definition of the schools; which, though perhaps not the most, exact, yet serves well enough to my present purpose.