positions: and those are of two sorts, mental and verbal.

Though in order to form a clear notion of Truth, it is necessary to consider Truth of thought distinct from Truth of words, yet we must treat of mental propositions in words, so that they become verbal.

What makes it more difficult to treat them separately is, that most men in reasoning with themselves use words instead of ideas, when the subject of their meditation contains complex ideas, because these ideas are generally confused and undetermined. Manj who talk much of religion and conscience, of church and faith, of power and right, &c. would perhaps have little left in their 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.

A mental Proposition is the joining or separating of ideas in the mind:-a verbal proposition is the joining or separating of words in affirmative or nega

tive sentences.

Truth may be distinguished into verbal and real Verbal Truth is the use of terms according to the agreement or disagreement of our ideas, withou considering whether these ideas have an existence i nature. Real Truth is the use of signs according to the relation of those ideas which agree with th reality of things.

Falsehood is the marking down in words the agreement or disagreement of ideas otherwise than it is.

General Truths are most sought for; as by their comprehensiveness they enlarge our view and shorten our way to knowledge.

CHAP. VI.

OF UNIVERSAL PROPOSITIONS, THEIR TRUTH AND CERTAINTY.

THE prevailing custom of using Sounds for Ideas makes the consideration of Words and Propositions so necessary a part of the treatise of knowledge, that it is very hard to speak intelligibly of the one without explaining the other.

As our knowledge of General Truths cannot well be made known, and is seldom apprehended, but as conceived and expressed in words, it will be our business to enquire into the truth and certainty of universal propositions.

Not to be misled by the doubtfulness of terms, which is the danger every where, we must observe that certainty is of two kinds,-of Truth, and of Knowledge. Certainty of truth is the putting of

words together in propositions so as exactly to express the agreement or disagreement of the ideas they signify. Certainty of knowledge is the perception of the agreement or disagreement of ideas as expressed in any proposition. To be certain of the truth of any general proposition we must know the essence of each species its terms stand for. This we may easily do in all simple ideas and modes, because the real and nominal essence is the same, that is, the abstract idea, which the general term denotes, is the sole esBut in substances a real essence distinct from the nominal being supposed to determine the species, the extent of the general term is uncertain. If men would apply general terms strictly to the nominal essence alone, there would be no doubt about the truth of propositions..

sence.

I have chosen to use the scholastic terms essences and species on purpose to shew the absurdity of thinking them any other realities than abstract ideas with names affixed to them. I might perhaps have treated of these things in a better and clearer way, but that I thought it necessary to discover and remove those wrong notions of essences or species which the prevalence of scholastic learning has too generally inculcated.

The names of substances when used as they should be, for the ideas men have in their minds, carry a clear and determinate signification with them; but

will not serve for universal propositions of whose truth we can be certain; because their complex ideas are such combinations of simple ones as have no discoverable connexion or repugnancy but with very few other ideas. No one, I think, can certainly know from the colour of any body what smell, taste, sound, or tangible qualities it has, or what alterations it is capable of making on or receiving from other bodies.

How much the being and operation of particular substances in this our globe depend on causes utterly beyond our view, it is impossible for us to determine. The parts of this stupendous universe may have such a connexion, that the things of this Earth would cease to be what they are, if some incomprehensibly remote star should cease to move or be as it is.

Inquisitive and observing men may by strength of judgment, and on probabilities taken from wary observation, often guess right at what experience has not discovered: but this still is only opinion and not knowledge. Let our abstract idea of man be a body of such a shape, with sense, voluntary motion, and reason; and we cannot with certainty affirm that all men sleep by intervals -no man can be nourished by wood or stones;-all men will be poisoned by hemlock-because these ideas have no necessary connexion or repugnancy with the nominal essence or abstract idea.

CHAP. VII.

OF MAXIMS.

MAXIMS and Axioms have passed for principles of science; and being self-evident have been supposed innate. Several other truths, not allowed to be axioms, are equally self-evident.

1st, The immediate perception of Identity or Diversity, being founded in the mind's having distinct ideas, affords as many self-evident propositions as we have distinct ideas: for we need only understand the terms to perceive the truth of what is affirmed or denied concerning the agreement or disagreement of the ideas:-that a man is not a horse, that blue is not red, is as self-evident as that whatever is, is.

2dly, of Co-existence, or such necessary connexion between two ideas that the existence of one always supposes that of the other, we have but few intuitive ideas. The idea of filling a place equal to the contents of its superficies being annexed to our idea of body, I think this proposition intuitive; "that two bodies cannot be in the same place."

Sdly, As to the relations of modes, Mathematicians have framed, many axioms concerning that of equality: as Equals taken from equals, the re