CHAPTER V.

Of Truth in General.

Truth, in the proper import of the word, signifies the joining or separating of signs; as the things signified by them do agree or disagree one with another. The joining or separating of signs, is what we call propositions; so that truth properly belongs only to propositions; whereof there are two sorts, mental and verbal, as there are two sorts of signs commonly made use of, ideas and words.

It is difficult to treat of mental propositions without verbal because in speaking of mental, we must make use of words, and then they become verbal. Again, men commonly, in their thoughts and reasonings, use words instead of ideas; especially if the subject of their meditation contains in it complex ideas. If we have occasion to form mental propositions about white, black, circle, &c. 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, &c. we usually put the name for the idea; because the idea these names stand for, being for the most part confused, imperfect, and undetermined; we reflect on the names themselves, as being more clear, certain, distinct, and readier to occur to our thoughts, than 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.

We must then observe two sorts of propositions, that we are capable of making: 1. mental propositions, wherein the ideas in our understandings are put together, or separated by the mind, perceiving or judging of their agreement or disagreement; 2. verbal

propositions, which are words put together or separate in affirmative or negative sentences: so that proposition consists in joining or separating signs: and truth consists in putting together, or separating these signs, according as the things they stand for agree or disagree.

Truth, as well as knowlege, may well come under the distinction of verbal and real; that being only verbal truth, wherein terms are joined according to the agreement or disagreement of the ideas they stand for, without regarding whether our ideas are such as really have, or are capable of having an existence in nature. But then it is they contain real truth, when these signs are joined, as our ideas agree; and when our ideas are such as we know are capable of having an existence in nature; which in substances we cannot know, but by knowing that such have existed.

Truth is the marking down in words the agreement or disagreement of ideas, as it is. Falsehood is the marking down in words the agreement or disagreement of ideas, otherwise than it is; and so far as these ideas thus marked by sounds, agree to their archetypes, so far only is the truth real. The knowlege of this truth consists in knowing what ideas the words stand for, and the perception of the agreement or disagreement of those ideas, according as it is marked by those words.

Besides truth taken in the strict sense before mentioned, there are other sorts of truths: as, 1. moral truth, which is, speaking things according to the persuasion of our own minds; 2. metaphysical truth, which is nothing but the real existence of things conformable to the ideas to which we have annexed their

names.

These considerations of truth either having been before taken notice of, or not being much to our present purpose, it may suffice here only to have mentioned them.

CHAPTER VI.

Of universal Propositions, their Truth and Certainty.

The prevailing custom of using sounds for ideas, even when men think and reason within their own breasts, makes the consideration of words and propositions so necessary a part of the treatise of knowlege, that it is very hard to speak intelligibly of the one, without explaining the other. And since general truths, which with reason are most sought after, can never be well made known, and are seldom apprehended, but as conceived and expressed in words; it is not out of our way, in the examination of our own knowlege, to inquire into the truth and certainty of universal knowlege.

But it must be observed, that certainty is twofold, certainty of truth, and certainty of knowlege. Certainty of truth is, when words are so put together in propositions, as exactly to express the agreement or disagreement of the ideas they stand for, as really it is. Certainty of knowlege, is to perceive the agreement or disagreement of ideas as expressed in any propositions. This we usually call knowing, or being certain of the truth of any proposition.

Now because we cannot be certain of the truth of any general proposition, unless we know the precise bounds and extent of the species its terms stand for; it is necessary we should know the essence of each species, which is that which constitutes and bounds it. This in all simple ideas and modes is not hard to do: for in these the real and nominal essence being the same, there can be no doubt how far the species extends, or what things are comprehended under each term: which it is evident are all that have an exact conformity with the ideas it stands for, and no other. But in substances wherein a real essence, distinct from the nominal, is supposed to constitute and bound the

species, the extent of the general word is very uncertain; because, not knowing this real essence, we cannot know what is, or is not of that species, and consequently what may, or may not with certainty be affirmed of it.

Hence we may see that the names of substances, when made to stand for species, supposed to be constituted by real essences, which we know not, are not capable of conveying certainty to the understanding. Of the truth of general propositions made up of such terms we cannot be sure. For how can we be sure that this or that quality is in gold, for instance, when we know not what is, or is not gold; that is, what has, or has not the real essence of gold, whereof we have no idea at all.

On the other side, the names of substances, when made use of for the complex ideas men have in their minds; though they carry a clear and determinate signification with them, will not yet serve us to make many universal propositions, of whose truth we can be certain because the simple ideas, out of which the complex are combined, carry not with them any discoverable connexion of repugnancy, but with a very few other ideas.

For instance, All gold is fixed, is a proposition we cannot be certain of, how universally soever it be believed for if we take the term gold to stand for a real essence, it is evident we know not what particular substances are of that species, and so cannot with certainty affirm any thing universally of gold. But if we make the term gold stand for a species, determined by its nominal essence, be its complex idea what it will; for instance, a body yellow, fusible, malleable, and very heavy; no quality can with certainty be denied or affirmed universally of it, but what has a discoverable connexion, or inconsistency with that nominal essence. Fixedness, for instance, having no necessary connexion that we can discover

with any simple idea that makes the complex one, or with the whole combination together; it is impossible that we should certainly know the truth of this proposition, All gold is fixed. But is not this an universal certain proposition, All gold is malleable? I answer, it is so, if malleableness be a part of the complex idea the word gold stands for: but then here is nothing affirmed of gold, but that, that sound stands for an idea, in which malleableness is contained. And such a sort of truth and certainty it is, to say a centaur is four-footed.

I imagine amongst all the secondary qualities of substances, and the powers relating to them, there cannot any two be named, whose necessary coexistence or repugnance to coexist can be certainly known, unless in those of the same sense, which necessarily exclude one another. Thus by the color we cannot certainly know what smell, taste, &c. any body is of.

It is no wonder then that certainty is to be found but in very few general propositions concerning substances: our knowlege of their qualities and properties goes very seldom farther than our senses reach, or inform us. Inquisitive and observing men may, by strength of judgment, penetrate farther; and on probabilities taken from wary observations and hints well laid together, often guess right at what experience has not yet discovered to them: but this is but guessing still; it amounts only to opinion, and has not that certainty which is requisite to knowlege.

To conclude: General propositions, of what kind soever, are then only capable of certainty, when the terms used in them stand for such ideas, whose agreement or disagreement, as there expressed, is capable to be discovered by us and we are then certain of their truth or falsehood, when we perceive the ideas they stand for, to agree or not agree, according as they are affirmed or denied one of another; whence