Direct suicide on one's own authority may happen in two ways: positively, that is, by doing an act which is directly homicidal; or negatively, by omitting an act necessary for the preservation of life. That a negative homicide be direct, death must be intended as an end or means. If, however, one voluntarily intends an end or a means, but for the sake of antecedent good or evil omits some act necessary to preserve life, his suicide is indirect, _per accidens_, and not always illicit unless there is a precept against just such an omission. Man has no dominion over his own life, he has only the use of it; and the natural law obliges us while using a thing which is under the dominion of another not to omit ordinary means for its preservation. We are not, however, held to extraordinary means. His own death is criminally imputable to him who negatively and indirectly kills himself by omitting the ordinary means for preserving his life, because the precept he is under to preserve his own life makes his act voluntary. If he omits extraordinary means, the death is not criminally imputable to him because there is no precept obliging such means. Certain circumstances may by accident oblige one to use extraordinary means to preserve one's own life--a dependent family, a public office in perilous times, or the like. The proposition, then, is: The natural law does not give a man absolute dominion over his own life. I. The natural law gives no rights except such as are finally founded in human nature itself; but human nature cannot give a title to dominion over one's own life; therefore the natural law does not give man such a right. Every natural right is either congenital or acquired. The title to a congenital right is human nature itself; the title to an acquired right is some act consequent to the exercise of human activity. The right to such exercise is, in turn, congenital and founded in human nature. If nature established the title to dominion over one's own life it would thereby establish the power of destroying that life, and thus of removing the fundamental title to all rights; but nature exists as the foundation for rights, not for the subversion of rights; therefore human nature cannot give a final title to dominion over our own life. Again, this minor of the first argument is confirmed by the fact that if nature even remotely established the power of self-destruction there should be in nature itself some natural tendency to such destruction, but the direct contrary is the fact. II. The natural law cannot grant a right to man which is not a means to the common end of human life; but absolute dominion over one's own life is not such a means, therefore the natural law cannot give one dominion over his own life.