Fr. Engels sums up the achievement of his friend Marx in the two great discoveries—the materialistic conception of history, and the revelation of the secret of the capitalistic method of production by means of surplus value. Materialism is a very old theory of the world. It is now given up by competent thinkers, and we need not discuss it here. Nor need we say that it is a grave exaggeration to maintain that all social institutions, including philosophy and religion, are to be explained by reference to the economic factors. History is a record of the activity of the human mind in very many directions. Men have had various interests, which have had a substantive, and so far, an independent value, though they must also be regarded as an organic whole. It is absolutely impossible to account for all by reference to any one. Nevertheless, it is a great merit of Marx that he has so powerfully called attention to the vast importance of the economic side of history. The economic factors in the life of mankind have been sadly neglected, even by philosophic historians. Such neglect has been partly due to the scarcity of material relating to this aspect of their subject, partly owing to false conceptions of the function of the historian, chiefly because their public was a high-bred class, which had no particular wish to read about such unfashionable topics as those connected with the daily toil of the lower orders. In this way the true causation of history has often been overlooked, or totally misconceived, and results have, in thousands of instances, been traced to conventional and imaginary agencies, when the real origin lay deep down in the economic life of the people. We are now beginning to see that large sections of history will need to be rewritten in this new light.