5. He is a prudent man, that can give counsel to others and to himself in order to the attainment of ends that are worthy of human endeavour. If unworthy ends are intended, however sagaciously they are pursued, that is not prudence. We may call it _sagacity_, or _shrewdness_, being a habit of ready discernment and application of means to ends. Napoleon I. was conspicuous for this sagacity. It is the key to success in this world. But prudence discovers worthy ends only, and to them only does it provide means. The intellect is often blinded by passion, by desire and by fear, so as not to discern the proper end and term to make for in a particular instance and a practical case. The general rules of conduct remain in the mind, as that, "In anger be mindful of mercy:" but the propriety of mercy under the present provocation drops out of sight. The intellect does not discern the golden mean of justice and mercy in relation to the circumstances in which the agent now finds himself. In other words, the habit of prudence has failed; and it has failed because of the excess of passion. Thus prudence is dependent on the presence of the virtues that restrain passion, namely, fortitude and temperance. A like argument would hold for the virtue of justice, that rectifies inordinate action in dealing with another. The conclusion is, that as the moral virtues cannot exist without prudence, so neither can prudence exist without them: for vice corrupts the judgment of prudence. 6. Hence we arrive at a settlement of the question, whether the virtues can be separated, or whether to possess one is to possess all. We must distinguish between the rudimentary forms of virtue and the perfect habit. The rudimentary forms certainly can exist separate: they are a matter of temperament and inherited constitution: and the man whom nature has kindly predisposed to benevolence, she has perhaps very imperfectly prepared for prudence, fortitude, or sobriety. But one perfect habit of any one of the four cardinal virtues, acquired by repeated acts, and available at the call of reason, involves the presence, in a matured state, of the other three habits also. A man who acts irrationally upon one ground, will behave irrationally on other grounds also: or if his conduct be rational there, it will not be from regard for reason, but from impulse, temperament, or from some other motive than the proper motive of the virtue which he seems to be exercising. _Readings_.--St. Thos., 1a 2æ, q. 54, art. 4; _ib_., q. 58, art. 5, in corp.; _ib_., 2a 2æ, q. 47, art. 7, 12, 13; Ar., _Eth_., VI., v.; _ib_., VI., xii., 9, 10; _ib_., VI., xiii., 6; St. Francis of Sales, _Of the Love of God_, bk. xi., c. vii. SECTION VII.--_Of Temperance_.