 This enables us to see how Aristotle’s treatment of the intellectual virtues does give greater content and precision to the doctrine of the mean. The best standard is the one adopted by the philosopher; the second-best is the one adopted by the political leader. In either case, it is the exercise of an intellectual virtue that provides a guideline for making important quantitative decisions. This supplement to the doctrine of the mean is fully compatible with Aristotle’s thesis that no set of rules, no matter how long and detailed, obviates the need for deliberative and ethical virtue. If one chooses the life of a philosopher, one should keep the level of one’s resources high enough to secure the leisure necessary for such a life, but not so high that one’s external equipment becomes a burden and a distraction rather than an aid to living well. That gives one a firmer idea of how to hit the mean, but it still leaves the details to be worked out. The philosopher will need to determine, in particular situations, where justice lies, how to spend wisely, when to meet or avoid a danger, and so on. All of the normal difficulties of ethical life remain, and they can be solved only by means of a detailed understanding of the particulars of each situation. Having philosophy as one’s ultimate aim does not put an end to the need for developing and exercising practical wisdom and the ethical virtues.