Again, the argument that suicide is cowardice is not broad enough. Fortitude is a mean between fear and rashness, and this argument maintains that the suicide sins against fortitude by rashness. If we have good reason it is not rash to expose ourselves to death; the soldier may do so, the person struggling to save a neighbor's life, and so on; it may be the highest form of fortitude thus to expose oneself to death. If the suicide can persuade himself that by his act he is seeking greater good than the life he possesses he would have reason for his act, and at least be above cowardice. This argument is one that can be turned at times so as to cut the fingers of the man that uses it. The fundamental reason that suicide is not lawful is that man cannot be master of his own life, and therefore he may not dispose of it as he pleases. Suicide is the direct killing of oneself on one's own authority. A killing is _direct_ when death is intended as an end, or chosen as a means to an end. Direct killing is positive by commission, or negative by omission. In such cases the will directly rests in the death as a voluntary and free act. A killing is _indirect_ when the act of which death is the effect by its nature and the intent of the agent is directed toward another end, but concomitantly, or as a consequence, results in death. In such case death is an accidental effect, and comes indirectly from the activity of the will--it is not necessarily voluntary. If one has a right to do that other deed, or if it is his duty to do it, and there is a proportion between it and his life, he may do the deed and permit the consequent death. A direct homicide may be done on one's own authority, or on that of another person. It is done on one's own authority if the agent assumes a natural individual dominion over life, and by virtue of such dominion directly kills himself or another; it is done on the authority of another when a man directly kills himself or another by the mandate of a positive divine or human law, and in the name and on the authority of a positive divine or human legislator. It is evident that God, as Creator, has supreme dominion over human life, and therefore by his positive authority he may command a man directly to kill himself. God, however, does not by the natural law confer on man the right thus to kill. The question here is of the natural duty or right which comes from the natural law alone.