Locke cannot be truly regarded as the author of sensationalism any more than of idealism. His system is based upon experience, but with him experience includes reflection as well as sense. His analysis and construction of ideas has no foundation in fact; it is only the dialectic of the mind ‘talking to herself.’ The philosophy of Berkeley is but the use of one word instead of two, which have the same meaning with it. For objects of sense he would substitute sensations. He imagines himself to have changed the relation of the human mind towards God and nature; they remain the same as before, though he has drawn the imaginary line by which they are divided at a different point. He has annihilated the outward world, but it instantly reappears governed by the same laws and described under the same names. [Sidenote: _Philosophy and the history of philosophy._] A like remark applies to David Hume, of whose philosophy the central principle is the denial of the relation of cause and effect. He would deprive men of a familiar term which they can ill afford to lose; but he seems not to have observed that this alteration is merely verbal and does not in any degree affect the nature of things. Still less did he remark that he was arguing from the necessary imperfection of language against the most certain facts. And here, again, we may find a parallel with the ancients. He goes beyond facts in his scepticism, as they did in their idealism. Like the ancient Sophists, he relegates the more important principles of ethics to custom and probability. But crude and unmeaning as this philosophy is, it exercised a great influence on his successors, not unlike that which Locke exercised upon Berkeley and Berkeley upon Hume himself. All three were both sceptical and ideal in almost equal degrees. Neither they nor their predecessors had any true conception of language or of the history of philosophy. Hume’s paradox has been forgotten by the world, and did not any more than the scepticism of the ancients require to be seriously refuted. Like some other philosophical paradoxes, it would have been better left to die out. It certainly could not be refuted by a philosophy such as Kant’s, in which, no less than in the previously mentioned systems, the history of the human mind and the nature of language are almost wholly ignored, and the certainty of objective knowledge is transferred to the subject; while absolute truth is reduced to a figment, more abstract and narrow than Plato’s ideas, of ‘thing in itself,’ to which, if we reason strictly, no predicate can be applied. [Sidenote: _Possibility of a new method._]