7. The first distinction of names is, that some are _positive_, or _affirmative_, others _negative_, which are also called _privative_ and _indefinite_. _Positive_ are such as we impose for the likeness, equality, or identity of the things we consider; _negative_, for the diversity, unlikeness, or inequality of the same. Examples of the former are, _a man_, _a philosopher_; for a _man_ denotes any one of a multitude of men, and _a philosopher_, any one of many philosophers, by reason of their similitude; also, _Socrates_ is a positive name, because it signifies always one and the same man. Examples of _negatives_ are such positives as have the negative particle _not_ added to them, as _not-man_, _not-philosopher_. But positives were before negatives; for otherwise there could have been no use at all of these. For when the name of _white_ was imposed upon certain things, and afterwards upon other things, the names of _black_, _blue_, _transparent_, _&c._ the infinite dissimilitudes of these with _white_ could not be comprehended in any one name, save that which had in it the negation of white, that is to say, the name _not-white_, or some other equivalent to it, in which the word _white_ is repeated, such as _unlike to white_, _&c._ And by these _negative names_, we take notice ourselves, and signify to others what we have not thought of. [Sidenote: Contradictory names.] 8. Positive and negative names are _contradictory_ to one another, so that they cannot both be the name of the same thing. Besides, of contradictory names, one is the name of anything whatsoever; for whatsoever is, is either man, or not-man, white or not-white, and so of the rest. And this is so manifest, that it needs no farther proof or explication; for they that say _the same thing cannot both be, and not be_, speak obscurely; but they that say, _whatsoever is, either is, or is not_, speak also absurdly and ridiculously. The certainty of this axiom, viz. _of two contradictory names, one is the name of anything whatsoever, the other not_, is the original and foundation of all ratiocination, that is, of all philosophy; and therefore it ought to be so exactly propounded, that it may be of itself clear and perspicuous to all men; as indeed it is, saving to such, as reading the long discourses made upon this subject by the writers of _metaphysics_ (which they believe to be some egregious learning) think they understand not, when they do. [Sidenote: A common name.]