To trace Locke's influence on subsequent speculation would be to write the History of Philosophy from his time to our own. In England, France, and Germany there have been few writers on strictly philosophical questions in this century or the last who have not either quoted Locke's _Essay_ with approbation, or at least paid him the homage of stating their grounds for dissenting from it. In the last century, his other works, especially those on Government and Toleration, may be said to have almost formed the recognized code of liberal opinion in this country, besides exercising a considerable influence on the rapidly developing speculations which, in the middle of the century, were preparing an intellectual no less than a social revolution in France. I can here only speak of the nature of Locke's influence, and of the directions it took, in the very broadest outline, and it is the less necessary that I should enter into detail, as I have frequently adverted to it in the preceding chapters. In England, the _Essay_, though from the first it had its ardent admirers, seemed, for some years after its appearance, to have produced its effect on English philosophical literature mainly by antagonism. Many were the critics who attacked the "new way of ideas," and attempted to show the evil consequences to morals, religion, and exact thought which must follow from the acceptance of Locke's speculations. Here and there he was defended, but the attack certainly largely outnumbered the defence. Of these controversies I have already given some account in the chapters on Locke's Life, and need not, therefore, now recur to them. The first English writer on philosophy of the highest rank who succeeded Locke was Berkeley, and on him the influence of his predecessor is so distinctly apparent, that it may well be questioned whether Berkeley would ever have written the _Principles_ and the _Dialogues_, if Locke had not written the _Essay_. Locke had regarded not "things" but "ideas" as the immediate objects of the mind in thinking, though he had supposed these ideas to be representative of things; but why, argued Berkeley, suppose "things" to exist, if "ideas" are the only objects which we perceive? Again, Locke had analyzed the idea of Matter conceived as "Substance" into "we know not what" support of known qualities. How, then, said Berkeley, do we know that it exists? The idealist philosophy of Berkeley may thus be viewed as a development, on one side, of the philosophy of Locke. But Hume, by carrying Berkeley's scepticism further than he had done himself, and by questioning the reality of Substance, as applied either to matter or mind, may be said to have developed Locke's principles in a direction which was practically the very reverse of that taken by Berkeley. For the result of Berkeley's denial of "matter" was to enhance the importance of "mind," and to re-assure men as to the existence of one all-embracing mind in the person of the Deity.