Those physicians were wise who, at a recent congress, voted to refuse making any statement upon the problems of responsibility propounded to them by the courts. What does responsibility mean? Where does it begin? What are its boundaries? One finds himself here not in the presence of a question of simple legal medicine; to speak of responsibility is to speak of free will, and to speak of free will is to be plunged into the fundamental mysteries of human philosophy. These mysteries, to tell the truth, are mysteries only because it is to man's interest that things should be so. We are accustomed to consider human acts as free acts, voluntarily consented to; the adoption of a contrary view would so interfere with our habits that social life would become exceedingly difficult. Our teachers or experience have taught us that our body is capable of two kinds of movement,--the one involuntary and necessary, such as respiration, or the circulation of the blood, and the other voluntary, accomplished at will,--the movement of our limbs, our tongue, our lips. But a closer examination would soon show us that this division is very arbitrary. It is impossible for us to make our heart stop beating; but is it really possible to stop our finger from moving, and if it is, for how long? We can cease eating: but for how long? We can even stop breathing; for how long? In reality, the freedom of our bodily movements, if it exists, is a limited freedom, a freedom exercised within a very narrow circle,--the freedom of a prisoner who can pace back and forth in his cell. Similarly, the exercise of our external activity is subjected to rather strict conditions: we can speak, walk, work in a thousand different ways, but during a certain time only. At the end of this time we feel that our freedom is exhausted we are at the end of our chain. There is nothing more to do: we must obey. In whatever direction we may turn we behold looming forth the obstacle that will certainly bar our way. Sometimes there is annexed to the prison a little courtyard where we may walk about a little, but this courtyard is itself only a prison: the boundary has been set back a few paces, that is all.