Others, too, start from the same point of view in combating the concept of free will. The germs of all the relevant arguments are to be found as early as Spinoza. All that he brought forward in clear and simple language against the idea of freedom has since been repeated times without number, but as a rule enveloped in the most hair-splitting theoretical doctrines, so that it is difficult to recognize the straightforward train of thought which is all that matters. Spinoza writes in a letter of October or November, 1674, “I call a thing free which exists and acts from the pure necessity of its nature, and I call that unfree, of which the being and action are precisely and fixedly determined by something else. Thus, for example, God, though necessary, is free because he exists only through the necessity of his own nature. Similarly, God cognizes himself and all else freely, because it follows solely from the necessity of his nature that he cognizes all. You see, therefore, that for me freedom consists not in free decision, but in free necessity..
 “But let us come down to created things which are all determined by external causes to exist and to act in a fixed and definite manner. To perceive this more clearly, let us imagine a perfectly simple case. A stone, for example, receives from an external cause acting upon it a certain quantity of motion, by reason of which it necessarily continues to move, after the impact of the external cause has ceased. The continued motion of the stone is due to compulsion, not to the necessity of its own nature, because it requires to be defined by the thrust of an external cause. What is true here for the stone is true also for every other particular thing, however complicated and many-sided it may be, namely, that everything is necessarily determined by external causes to exist and to act in a fixed and definite manner.
 “Now, please, suppose that this stone during its motion thinks and knows that it is striving to the best of its ability to continue in motion. This stone, which is conscious only of its striving and is by no means indifferent, will believe that it is absolutely free, and that it continues in motion for no other reason than its own will to continue. But this is just the human freedom that everybody claims to possess and which consists in nothing but this, that men are conscious of their desires, but ignorant of the causes by which they are determined. Thus the child believes that he desires milk of his own free will, the angry boy regards his desire for vengeance as free, and the coward his desire for flight. Again, the drunken man believes that he says of his own free will what, sober again, he would fain have left unsaid, and as this prejudice is innate in all men, it is difficult to free oneself from it. For, although experience teaches us often enough that man least of all can temper his desires, and that, moved by conflicting passions, he sees the better and pursues the worse, yet he considers himself free because there are some things which he desires less strongly, and some desires which he can easily inhibit through the recollection of something else which it is often possible to recall.
 Because this view is so clearly and definitely expressed it is easy to detect the fundamental error that it contains. The same necessity by which a stone makes a definite movement as the result of an impact, is said to compel a man to carry out an action when impelled thereto by any reason. It is only because man is conscious of his action that he thinks himself to be its originator. But in doing so he overlooks the fact that he is driven by a cause which he cannot help obeying. The error in this train of thought is soon discovered. Spinoza, and all who think like him, overlook the fact that man not only is conscious of his action, but also may become conscious of the causes which guide him. Nobody will deny that the child is unfree when he desires milk, or the drunken man when he says things which he later regrets. Neither knows anything of the causes, working in the depths of their organisms, which exercise irresistible control over them. But is it justifiable to lump together actions of this kind with those in which a man is conscious not only of his actions but also of the reasons which cause him to act? Are the actions of men really all of one kind? Should the act of a soldier on the field of battle, of the scientific researcher in his laboratory, of the statesman in the most complicated diplomatic negotiations, be placed scientifically on the same level with that of the child when it desires milk: It is no doubt true that it is best to seek the solution of a problem where the conditions are simplest. But inability to discriminate has before now caused endless confusion. There is, after all, a profound difference between knowing why I am acting and not knowing it. At first sight this seems a self-evident truth. And yet the opponents of freedom never ask themselves whether a motive of action which I recognize and see through, is to be regarded as compulsory for me in the same sense as the organic process which causes the child to cry for milk.