Whenever men commit injustice, it is either by stealing a deposit, or committing adultery, or thieving, or doing some other particular act of injustice; but no one ever robbed himself of a deposit, or committed adultery with his own wife, or stole his own property; so that if the commission of injustice lies in such things, and it is not possible to do any of them to oneself, it will not be possible to commit injustice against oneself.