1. Prudence is _right reason applied to practice_, or more fully it may be defined, the habit of intellectual discernment that enables one to hit upon the golden mean of moral virtue and the way to secure that mean. Thus prudence tells one what amount of punishment is proper for a particular delinquent, and how to secure his getting it. It is to be observed that prudence does not will the golden mean in question, but simply indicates it. To will and desire the mean is the work of the moral virtue concerned therewith: as in the case given it is the work of vindictive justice. 2. From the definition of moral virtue above given (c. v., s. iv., n. 4, p. 79), it is clear that no moral virtue can come into act without prudence: for it is the judgment of the prudent man that must define in each case the _golden mean_ in relation to ourselves, which every moral virtue aims at. Thus, without prudence, fortitude passes into rashness, vindictive justice into harshness, clemency into weakness, religion into superstition. 3. But may not one with no prudence to guide him hit upon the _golden mean_ by some happy impulse, and thus do an act of virtue? We answer, he may do a good act, and if you will, a virtuous act, but not an act of virtue, not an act proceeding from a pre-existent habit in the doer. The act is like a good stroke made by chance, not by skill; and like such a stroke, it cannot be readily repeated at the agent's pleasure. (See c. v., s. i., n. 4, p. 66; and Ar., _Eth_., II., iv., 2.) 4. Prudence in its essence is an intellectual virtue, being a habit resident in the understanding: but it deals with the subject-matter of the moral virtues, pointing out the measure of temperance, the bounds of fortitude, or the path of justice. It is the habit of intellectual discernment that must enlighten every moral virtue in its action. There is no virtue that goes blundering and stumbling in the dark.