155. Berkeley’s treatises, we must remember, though professedly philosophical, really form a theological polemic. He wrote as the champion of orthodox Christianity against ‘mathematical atheism,’ and, like others of his order, content with the demolition of the rival stronghold, did not stay to enquire whether his own untempered mortar could really hold together the fabric of knowledge and rational religion which he sought to maintain. He found practical ungodliness and immorality excusing themselves by a theory of ‘materialism’--a theory which made the whole conscious experience of man dependent upon ‘unperceiving matter.’ This, whatever it might be, was not an object which man could love or reverence, or to which he could think of himself as accountable. Berkeley, full of devout zeal for God and man, and not without a tincture of clerical party-spirit (as appears in his heat against Shaftesbury, whom he ought to have regarded as a philosophical yoke-fellow), felt that it must be got rid of. He saw, or thought he saw, that the ‘new way of ideas’ had only to be made consistent with itself, and the oppressive shadow must vanish. Ideas, according to that new way (or, to speak less ambiguously, feelings) make up our experience, and they are not matter. Let us get rid, then, of the self-contradictory assumption that they are either copies of matter--copies of that, of which it is the sole and simple differentia that it is not an idea, or its effects--effects of that which can only be described as the unknown opposite of the only efficient power with which we are acquainted--and what becomes of the philosopher’s blind and dead substitute for the living and knowing God? It was one thing, however, to show the contradictions involved in Locke’s doctrine of matter, another effectively to replace it. To the latter end Berkeley cannot be said to have made any permanent contribution. That explicit reduction of ideas to feelings ‘particular in time,’ which was his great weapon of destruction, was incompatible with his doing so. He adds nothing to the philosophy, which he makes consistent with itself, while by making it consistent he empties it of three parts of its suggestiveness. His doctrine, in short, is merely Locke purged, and Locke purged is no Locke. What is meant by relation of mind and matter?