For if we will curiously observe the way our mind takes in thinking and reasoning, we shall find, I suppose, that when we make any propositions within our own thoughts about white or black, sweet or Bitter, a triangle or a circle, we can and often do frame in our minds the ideas themselves, without reflecting on the names.  But when we would consider, or make propositions about the more complex ideas, as of a man, vitriol, fortitude, glory, we usually put the name for the idea:  because the ideas these names stand for, being for the most part imperfect, confused, and undetermined, we reflect on the names themselves, because they are more clear, certain, and distinct, and readier occur to our thoughts than the pure ideas:  and so we make use of these words instead of the ideas themselves, even when we would meditate and reason within ourselves, and make tacit mental propositions.  In substances, as has been already noticed, this is occasioned by the imperfections of our ideas:  we making the name stand for the real essence, of which we have no idea at all.  In modes, it is occasioned by the great number of simple ideas that go to the making them up.  For many of them being compounded, the name occurs much easier than the complex idea itself, which requires time and attention to be recollected, and exactly represented to the mind, even in those men who have formerly been at the pains to do it; and is utterly impossible to be done by those who, though they have ready in their memory the greatest part of the common words of that language, yet perhaps never troubled themselves in all their lives to consider what precise ideas the most of them stood for.  Some confused or obscure notions have served their turns; and many who talk very much of religion and conscience, of church and faith, of power and right, of obstructions and humours, melancholy and choler, would perhaps have little left in their thoughts and meditations, if one should desire them to think only of the things themselves, and lay by those words with which they so often confound others, and not seldom themselves also.

5.  Mental and Verbal Propositions contrasted.

But to return to the consideration of truth:  we must, I say, observe two sorts of propositions that we are capable of making:—­

First, mental, wherein the ideas in our understandings are without the use of words put together, or separated, by the mind perceiving or judging of their agreement or disagreement.

Secondly, verbal propositions, which are words, the signs of our ideas, put together or separated in affirmative or negative sentences.  By which way of affirming or denying, these signs, made by sounds, are, as it were, put together or separated from another.  So that proposition consists in joining or separating signs; and truth consists in the putting together or separating those signs, according as the things which they stand for agree or disagree.