pure, that is to say, true time. Indeed if we want to contemplate time as a pure concept separated from all foreign admixture, we are obliged to eliminate all the various events which occur in time, either successively or simultaneously, and thus imagine a time in which nothing occurs. By this means we have not permitted the concept time to be overcome by the general concept of existence, but we have thereby arrived at a pure time concept. All these contradictions and impossibilities are mere child's play compared with the confusion into which he plunges the universe with its self-sufficient commencement. If the universe was in a condition in which no change occurred in it, how did it ever manage to get from that state to one of change? Moreover, an absolute condition of absence of change existing from eternity cannot possibly get out of that state unaided so as to pass over to a condition of progress and change. A first cause of motion must therefore have come from the outside, from beyond the universe, which caused the movement. This first cause of motion is clearly only another term for God, The God and the Beyond of which Herr Duehring fancied that he had so nicely settled in his scheme of the universe, return sharpened and deepened in his natural philosophy. Further Herr Duehring says: "Where a fixed element of existence is capable of measurement, it will remain in unalterable stability. This is evident from material and mechanical force." The former quotation gives, it may be incidentally mentioned, a good example of Herr Duehring's axiomatic grandiloquence. Fixed quantities remain exactly the same, the quantity of mechanical force, once in the universe, is always the same. We will not dwell on this, so far as it is true, Descartes knew and said it three hundred years ago as regards philosophy, while in mechanical science the doctrine of the conservation of energy has been preached for the last twenty years. Herr Duehring has not improved upon it in so far as he limits it to mechanical energy. But where was mechanical energy at the period of unchangeableness? To this question Herr Duehring stubbornly refuses an answer. Where was the unchangeable mechanical force then, Herr Duehring, and what was it busy about? Answer: "The original state of the universe, or, better, the existence of unchangeable matter, not allowing of any changes in time, is a question which no mind can pass except one which sees the acme of wisdom in the destruction of its own powers." Therefore you must either take my original condition with your eyes shut, or I, the lusty Eugene Duehring, brand you as an intellectual eunuch. Some people might be quite alarmed about this, but we who have seen a few examples of Herr Duehring's powers, can let the elegant abuse pass and reiterate the question, "But how about that mechanical energy, Herr Duehring, if you please?"