selves perfect, and the objects fully within their scope,) falls, if I mistake not, under the one or the other of these two divisions.

DEMONSTRATIVE KNOWLEDGE, where the intervening proofs or ideas perform their part perfectly, approaches, as I have already observed, to the certainty of intuition. But it has generally been held that this kind of demonstration can only take place in the science of mathematics, or, in other words, in ideas of number, extension, and figure. I coincide, however, completely with Mr. Locke, in believing that the knowledge afforded by physics may not unfrequently be as certain. I have already stated that the knowledge we possess of our own existence is INTUITIVE. Our knowledge of the existence of a God is, on the contrary, DEMONSTRATIVE. Examine, then, the proofs of this latter knowledge, and see whether it be less certain. Am I asked where proofs to this effect are to be found? On every side they press upon us in clusters. — I cannot, indeed, follow them up at the present moment, for it would require a folio volume instead of the close of a single lecture; and I merely throw out the hint that may pursue it at home. But this I may venture to say, that whatever cluster we take, it will develope to us a certain proof, and, in its separate value, fall but little short of the force of self-evidence. If I ascend into heaven he is there; in peerless splendour, in ineffable

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majesty; diffusing, from an inexhaustible fountain, the mighty tide of light, and life, and love, from world to world, and from system to system. If I descend into the grave he is there also; still actively and manifestly employed in the same benevolent pursuit: still, though in a different manner, promoting the calm but unceas ing career of vitality and happiness; harmoniously leading on the silent circle of decomposition and re-organization; fructifying the cold and gloomy regions of the tomb; rendering death itself the mysterious source of reproduction and new existence; and thus literally making the "dry bones live," and the "dead sing praises" to his name. If I examine the world without me, or the world within me, I trace him equally to a demonstration: - I feel, - nay, more than feel, — I know him to be eternal, omniscient, omnipotent, the creator of all things, and therefore God. I discover him, not by the vain maxims of tradition, or the visionary conceit of innate principles, but by the faculty with which he has expressly endowed me to search for him, by my reason. There may, perhaps, be some persons, as well learned as unlearned, who have never brought together these proofs of his existence, and are therefore ignorant of him; as there certainly are others, who have never brought together the proofs that the three angles of a triangle are equal to two right angles, and are therefore ignorant of geome

try: but both facts have a like truth and a like foundation: both flow from and return to the same fountain: for God is the author of for God is truth itself. every truth,

116

LECTURE V.

ON ANCIENT AND MODERN SCEPTICS.

FROM

ROM a system that is simple, intelligible, and satisfactory, adapted to the condition of man, and pregnant with useful instruction, we have now to turn our attention to a variety of hypotheses, that are scarcely in any instance worthy of the name of systems, and which it is difficult to describe otherwise than by reversing the terms we have just employed, and characterising them as complicated, unintelligible, unsatisfactory; as not adapted to the condition of man, and barren of useful instruction.

It is a distinguishing and praiseworthy feature in the Essay on Human Understanding, that it confines itself to the subject of human understanding alone, and that in delineating the operations of the mind, it neither enters into the question of the substance of mind, or the substance of matter; neither amuses us with speculations how external objects communicate with the senses, or the senses with the mental organ. It builds altogether upon the sure foundation of the simple fact, that the senses are influenced, and that they influence the mind; and as, in

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the former case, it calls the cause of this influence external objects, so in the latter case it calls the effects it produces internal ideas. Of the nature of these objects it says little, but of their substantive existence; of the nature of these ideas it says little, but of their truth or exact correspondence with the objects that excite them; its general view of the subject being reducible to the two following propositions :

First, that as objects are perceivable at a distance, and bodies cannot act where they are not, it is evident that something must proceed from them to produce impulse upon the senses, and that the motion hereby excited must be thence continued by the nerves, or connecting chain, to the brain or seat of sensation, so as to produce in our minds the particular ideas we have of them.*

And, secondly, that the ideas thus produced, so far from being images or pictures of the objects they represent, have no kind of resemblance to them, except so far as relates to their real qualities of solidity, extension, figure, motion, or rest and number. †

Thus far, and thus far only, does the author of the Essay on Human Understanding indulge in a digression into physical science; and even for this he feels it necessary to offer an apology to his reader: "I hope," says he, "I shall be pardoned this little excursion into natural philosophy, it being necessary in our present enquiry.”‡

* Essay on Hum. Underst. Book ii. ch. viii. § 12.

+ Ibid. § 15.

Ibid. § 22.