 We are now in a position to see how specifically the solid principles of philosophy strengthen morality. True philosophy (i.e., sound metaphysics) aids morality by providing grounds for assurance that in the end happiness is directly proportioned to merit. The more virtuous one is, the greater the happiness one can expect because one's well-being does not completely depend on the goods of this life and because it is incompatible with God's universal benevolence and infinite wisdom that even a single virtuous deed should go unrewarded and a vicious one unpunished. “After this,” Leibniz concludes, “it must be imprudent not to be just, because no one will fail to derive good or evil from what he will have done, according as it is just or unjust” (PW, “Meditation on the Common Concept of Justice,” pp. 58–9). Even though exceptional individuals may be able to remain virtuous at any apparent mortal cost, it follows from Leibniz's metaphysics that there is in fact no mortal price to pay for being virtuous. On the contrary, virtue is necessary and sufficient for true happiness (for further reading on Leibniz's natural law theory, see Brown 1995 and 2011a).