But a much ruder shock was soon afterwards given to a large part of Mr. Locke's system by the hand of Berkeley. Locke, believing firmly in the independent existence of the external world, yet seeing that the mind could take notice only of its own perceptions, imagined (according to the old doctrine of the schools,) that these perceptions, or ideas, must be exact resemblances of material things: and though he made a distinction between the primary and secondary qualities of matter, holding the former, as extension, solidity, and figure, to exist in the external things themselves; but the latter, as heat and colour, to exist only in the mind; yet, on the whole, his doctrine was, that our knowledge of the material world is obtained from the ideas or images of it introduced through the senses; "the one being the perfect resemblance of the other as they are in a mirror.*" This is what is generally

called the ideal theory, which, though manifestly hypothetical, incapable of proof, and almost unintelligible, has maintained its ground in this country against all opposition, and is, to this day, gravely taught to the young students of, at least, one of our universities. Against this theory Berkeley's metaphysical writings were principally directed; and the substance of his argument is pretty well given in the following passages: "As for our senses, by them we have the knowledge only of our sensations, ideas, or those things which are immedi

* Locke's Essay, Book ii. ch. 8.

ately perceived by sense, call them what you will but they do not inform us that things exist without a mind, or unperceived, like to those which are perceived." On the contrary," as there can be no notion or thought but in a thinking being, so there can be no sensation but in a sentient being its very essence consists in being felt. Nothing can resemble a sensation but a similar sensation in the same or some other mind, To think that any quality in a thing inanimate can resemble a sensation, is absurd, and a contradiction in terms." Whoever will be at the trouble of considering attentively these passages, will see, that, as against Mr. Locke and his followers, they are conclusive. How far they render doubtful, (supposing that to be possible,) the independent existence of the material world, which Dr. Reid and others say is made known to us in quite another manner from that described by Mr. Locke, is an entirely different question.

To another part of Mr. Locke's system, Mr. Stewart has himself furnished some considerable objections. They are borrowed, in substance, from Leibnitz and Lord Shaftesbury, but are arranged so much more skilfully by the writer who has adopted them than they had been by their first assertors, that he seems to have acquired some right to be considered as the proper owner. Locke maintained, that all our ideas are originally acquired from the perception of external objects, and of the opc

Principles of Human Knowledge, s. 18.

rations of our own minds; or, as he often expresses himself, from sensation and reflection. This is, in effect, saying that conciousness is exclusively the source of all our knowledge: and it would follow as a necessary inference, even though he had not distinctly so stated it, that "the understanding has not the power of inventing one new simple idea." The difficulties attending this doctrine will be sufficiently explained by the following extract from Mr. Stewart,

"There are a variety of notions so connected with our different intellectual faculties, that the exercises of the faculty may be justly regarded as a condition indispensably necessary to account for the first origin of the notion. Thus by a mind destitute of the faculty of memory, neither the ideas of time, nor of motion, nor of personal identity, could possibly have been formed; ideas, which are confessedly among the most familiar of all those we possess, and which cannot be traced immediately to consciousness by any effort of logical subtilty. In like manner, without the faculty of abstraction, we never could have formed the idea of number; nor of lines, surfaces, and solids, as they are considered by the mathematician; nor would it have been possible for us to comprehend the meaning of such words as classes or assortments, or indeed of any of the grammatical parts of speech but proper names. Without the power of reason or understanding, it is no less evident that no comment could have helped us to unriddle the import of the words, truth, certainty, probability, theorem, premises, conclusion; nor of any one of those which express the various sorts of relation which fall under our knowledge. In such cases, all that can be said, is, that the exercise of a particular faculty furnishes the occasion on

which certain simple notions are, by the laws of our constitution, presented to our thoughts; nor does it seem possible for us to trace the origin of a particular notion any farther than to ascertain what the nature of the occasion was, which in the first instance introduced it to our acquaintance.*"

It is manifest, that the objections here stated against Mr. Locke's theory are the same in kind with those above mentioned to have been urged by Leibnitz and Lord Shaftesbury, when they insist that certain innate ideas are necessarily unfolded by the exercise of our faculties. Existence, personal identity, and truth, are the ideas mentioned by Leibnitz. Order, administration, and the notion of a God, are specified by Lord Shaftesburyt. But Mr. Stewart, with the caution of an able commander, who knows the country in which he is acting, and the ambushes that may beset him, is not only careful to avoid the impropriety of terming the ideas which he specifies innate ideas, but avoids giving any opinion as to the manner in which they are acquired; only affirming, in contradiction to Mr. Locke, that they cannot be traced immediately to conciousness.

We feel very little disposition to enter into this controversy. It is of small importance how the ideas mentioned by Mr Stewart are acquired; whether, as seems most likely, by a rapid and almost intuitive act of the understanding, or by some less

Essay I. chap. ii. page 15.

+ See Letters to a Student at the University. Letter 8.

intelligible process, which we call a law of our constitution, because we know not what else to call it. We agree with him in thinking that they cannot be traced to consciousness; and we think, too, that Mr. Locke was rather rash in affirming that the understanding cannot frame one new simple idea. We do not, however, agree, that all the words mentioned by Mr. Stewart and Lord Shaftesbury express simple ideas. Time is not a simple notion, for it implies succession: so does motion: so does personal identity. Order is not a simple idea, for it the arrangement of several things: so does administration: and the idea of Deity is one of the most complex in nature. But existence is a simple idea; and it is not easy to see how it can be acquired, except by a rapid act of the understanding immediately. consequent upon perception.

supposes

Mr. Stewart appears to attach importance to the observations which we have above extracted; not on account of any anxiety he feels respecting the origin of our knowledge, but for a reason far better suited to his just and comprehensive understanding. That part of Mr. Locke's theory, which represents consciousness as the source of all our knowledge, has been made the ground work of some very pernicious opinions respecting morals. Dr. Hutcheson saw, that according to the received system, if right and wrong express simple ideas, their origin must be referred, not to reason, but to some appropriate power of perception. To this power he gave the name of the moral sense, little aware of the dangerous con