"One must substitute for false theories of freedom the actual conditions in which reason on the one hand and instinct on the other unite upon a middle ground. The fundamental facts of this sort of dynamics are to be learned from observation and as regards the calculation in advance of phenomena which have not yet occurred, we must judge of them in general terms according to their special qualities. In this way the silly speculations with respect to the freedom of the will which have wasted thousands of years are not only entirely removed but are replaced by something positive, something useful for practical life." So freedom of the will consists in this that reason impels men to the right and irrationality to the left and according to this parallelogram of forces the true direction is that of the diagonal. Freedom would therefore be the average between insight and impulse, between understanding and lack of understanding, and its degree would to use an astronomical expression be empirically established by the "personal equation." But a few pages later we read "We establish moral responsibility upon freedom by which we only mean susceptibility to known motives according to the measure of natural and acquired reason. All such motives in spite of antagonism realise themselves in action with the inevitability of natural law, but we count upon this inevitable necessity when we deal with morals." This second definition of freedom which is quite opposed to the first is nothing but a very weak paraphrase of Hegel's notions on the subject. Hegel was the first man to make a proper explanation of the relations of freedom and necessity. In his eyes freedom is the recognition of necessity. "Necessity is blind only in so far as it is not understood." Freedom does not consist in an imaginary independence of natural laws but in a knowledge of these laws and in the possibility thence derived of applying them intelligently to given ends. This is true both as regards the laws of nature and of those which control the spiritual and physical existence of man himself,--two classes of laws which we can distinguish as an abstraction but not in reality. Freedom of the will consists in nothing but the ability to come to a decision when one is in possession of a knowledge of the facts. The freer the judgment of a man then in relation to a given subject of discussion so much the more necessity is there for his arrival at a positive decision. On the other hand lack of certainty arising from ignorance which apparently chooses voluntarily between many different and contradictory possibilities of decision shows thereby its want of freedom, its control by things which it should in reality control. Freedom, therefore, consists in mastery over ourselves and external nature founded upon knowledge of the necessities of nature, it is, therefore, necessarily a product of historical development. The first human beings to become differentiated from the lower animals were in all