Two things seem to me to deserve some further explanation. What is the relation between historical materialism and socialism? Labriola, if I am not mistaken, is inclined to connect closely and almost to identify the two things. The whole of socialism lies in the materialistic interpretation of history, which is the truth itself of socialism; to accept one and reject the other is to understand neither. I consider this statement to be somewhat exaggerated, or, at least, to need explanation. If historical materialism is stripped of every survival of finality and of the benignities of providence, it can afford no apology for either socialism or any other practical guidance for life. On the other hand, in its special historical application, _in the assertion which can be made by its means_, its real and close connection with socialism is to be found. This assertion is as follows:--Society is now so constituted that socialism is the only possible solution which it contains within itself. An assertion and forecast of this kind moreover will need to be filled out before it can be a basis for practical action. It must be completed by motives of interest, or by ethical and sentimental motives, moral judgments and the enthusiasms of faith. The assertion in itself is cold and powerless. It will be insufficient to move the cynic, the sceptic, the pessimist. But it will suffice to put on their guard all those classes of society who see their ruin in the sequence of history and to pledge them to a long struggle, although the final outcome may be useless. Amongst these classes is the proletariat, which indeed aims at the extinction of its class. Moral conviction and the force of sentiment must be added to give positive guidance and to supply an imperative ideal for those who neither feel the blind impulse of class interest, nor allow themselves to be swept along by the whirling current of the times. The final point which I think demands explanation, although in this case also the difference between myself and Labriola does not appear to be serious, is this: to what conclusions does historical materialism lead in regard to the ideal values of man, in regard that is to intellectual truth and to what is called moral truth?