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Rh which express notions too simple to admit of analysis. Mr Locke claims this improvement as entirely his own; but the merit of it unquestionably belongs to Descartes, although it must be owned that he has not always sufficiently attended to it in his own researches.

2. His observations on the different classes of our prejudices;—particularly on the errors to which we are liable in consequence of a careless use of language as the instrument of thought. The greater part of these observations, if not the whole, had been previously hinted at by Bacon; but they are expressed by Descartes with greater precision and simplicity, and in a style better adapted to the taste of the present age.

3. The paramount and indisputable authority which, in all our reasonings concerning the human mind, he ascribes to the evidence of consciousness. Of this logical principle he has availed himself, with irresistible force, in refuting the scholastic sophisms against the liberty of human actions, drawn from the prescience of the Deity, and other considerations of a theological nature.

4. The most important, however, of all his improvements in metaphysics, is the distinction which he has so clearly and so strongly drawn between the primary and the secondary qualities of matter. This distinction was not unknown to some of the ancient schools of philosophy in Greece; but it was afterwards rejected by Aristotle, and by the schoolmen; and it was reserved for Descartes to place it in such a light, as (with the exception of a very few sceptical or rather paradoxical theorists) to unite the opinions of all succeeding inquirers. For this step, so apparently easy, but so momentous in its consequences, Descartes was not indebted to any long or difficult processes of reasoning; but to those habits of accurate and patient attention to the operations of his own mind, which, from his early years, it was the great business of his life to cultivate. It may be proper to add, that the epithets primary and secondary, now universally employed to mark the distinction in question, were first introduced by Locke; a circumstance which may have contributed to throw into the shade the merits of those inquirers who had previously struck into the same path.

As this last article of the Cartesian system has a close connection with several of the