no other assurance of them than some few trials will give; but whether they will succeed again another time, we cannot be certain: hence we have very few universal truths concerning natural bodies; and our reason carries us very little beyond particular matter of fact.

If such is our ignorance of material beings, how much less can we know any thing of the intellectual world of spirits; certainly a greater and more beautiful world than this, but of which we can frame no distinct ideas. Excepting a few superficial ideas of spirit, which we get by reflecting on our own spirit, and thence of the Author of all spirits, we have no certain information about it but by Revelation. Every thinking man has reason to be satisfied that other men have minds as well as himself; and the knowledge of his own mind cannot suffer him to be ignorant of a God: but who can know that there are degrees of spirits between us and God.

Again, we are incapable of Universal and Certain Knowledge wherever we cannot discover the connexion between our ideas; and as before, are left to the confined way of observation and experiment. The mechanical affections of bodies having no affinity with the ideas they produce, we can have no knowledge of them beyond our experience: and can only reason about them as incomprehensible effects produced by the appointment of an infinitely wise

agent: for there is no conceivable connexion between the impulse of a body and the perception of a colour or smell; that is, between the primary qualities of body, and our ideas of its secondary qualities. On the other side, it is as inconceivable how any thought should produce a motion in body, as how any body should produce a thought in the mind: constant experience alone convinces us of the fact, and not any connexion or necessary dependance of the ideas.

Some of our ideas seem so plainly to include certain relations in their own nature, that we cannot conceive them separable; and in these only are we capable of certain and universal knowledge: thus, the idea of a right lined triangle necessarily implies an equality of its angles to two right ones. This connexion is such that we cannot conceive it mutable or dependant on any arbitrary power.

As far as our observation teaches us that things proceed regularly, that certain effects constantly flow from certain causes, we may conclude that they act by some determined Law, though we know it not. In most things our knowledge extends no farther than particular experience of matter of fact; and by analogy we guess that at other times like causes will produce like effects.

Lastly, many truths are concealed from us not by any imperfection of our faculties, but by want of

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application to discover, examine, and compare those intermediate ideas which may shew us the habitudes · of things.

The ill use of words has contributed most to hinder the duc tracing of our ideas. Mathematicians accustoming themselves to consider ideas and not sounds, have avoided much of that perplexity, which has been the misfortune of a great part of the men of letters, and has made the stock of real knowledge bear so little proportion to the schools, disputes, and writings, with which the world has been filled.

We have hitherto examined the extent of our knowledge with respect to the sorts of things; we shall now consider its universality. When we perceive the relation of abstract ideas, our Knowledge is Universal: for what is known of such general ideas will be true of every particular thing in which that Essence (i. e. the abstract idea) is to be found.

CHAP. IV.

OF THE REALITY OF KNOWLEDGE.

My reader may perhaps object that, if knowledge consists in the perception of the agreement or disagreement of our ideas, the visions of an enthusiast,

and the reasonings of a sober man will be equally certain that a knowledge of men's own imaginations is nothing to a man that enquires after the reality of things.

I answer, that if our knowledge reach no farther than our ideas, where something farther is intended, our most serious thoughts will be little more than the reveries of a crazy brain: but I hope yet to shew that the knowledge of our own ideas gives us an assurance greater than bare imagination: and that it affords us all the certainty we can have of general Truths.

The mind knows not things immediately, but only by the intervention of its ideas : our knowledge therefore is only real, so far as there is a conformity between our ideas and the reality of things. The difficulty then is to find the criterion of this conformity; since the mind perceives nothing but its own ideas.

I think we may be assured that two sorts of our Ideas agree with things. 1st, We have shewn that the mind cannot make to itself any simple ideas which are the effects of things operating naturally, and producing those perceptions which the will of our maker has appointed. 2dly, All our

complex ideas, except of substances, being themselves archetypes, can never be capable of a wrong representation, because they are compared with nothing. Our knowledge of Mathematical Truths is no

doubt certain and real; yet we shall find that it is only the knowledge of ideas. A mathematician considers the properties of a rectangle or circle only as they exist in his mind; for perhaps he never found either of them existing precisely true: yet his knowledge of their properties is certain, because his reasonings relate no farther to such figures really existing, than as the figures themselves agree with their archetypes, which are his own ideas. Hence moral knowledge is equally capable of demonstration; our moral ideas being themselves archetypes, and of course adequate and complete.

Most of the discourses of those who enquire after Truth consist of general propositions and notions, in which existence is not at all concerned: for the demonstrations and maxims of Mathematicians and Moralists will be equally true in speculation, i. e. in idea, though there exist no Figures or Characters exactly conformable to their ideas. But it may be said, that if moral ideas are of our own making, our notions of virtue and vice will be very confused-no more than in Mathematicks, where if you keep the same precise idea, the figure being once drawn and seen makes the name of no force. Let a man have a clear idea that Injustice is the taking from others, without their consent, what by honest industry they have acquired, and he will not be misled by another person's giving the name of justice to the