In the Aristotelian conception of the good life reason is an important factor in the achievement of all the virtues. It is an essential element in the doctrine of the golden mean which tells us that a virtue is the point which is midway between the extremes of excess and deficiency. The determination of this point will vary with individuals and their respective circumstances for it is not the mathematical mean but the organic mean as determined by "reason" that prescribes what each individual ought to do. This is an important point in Aristotle's ethics for quite in contrast with what some moralists of the present day are advocating, he does not believe that the nature of goodness is purely a matter of satisfying one's desires. To be sure he recognizes that desires are an important element in the good life but unless these desires are given guidance and direction by the reason they may hinder rather than promote the realization of the good life.
In view of the fact that reason is the guiding element in all of the virtues it may seem strange that an entire book of the Ethics should be devoted to the intellectual virtues thus implying a distinction between the intellectual virtues and the moral virtues. There is a sound basis for this distinction although it does not mean that the two types of virtues are entirely separate or that either one functions independently of the other. The distinction is primarily that of means and ends. In the moral virtues the emphasis is placed on the proper control of one's appetites and desires. This must be done as a means toward the achievement of some larger and more inclusive end. Temperance thus becomes a means toward the acquisition of good health. Courage which always involves a risk is a necessary means for the further development of one's capacities and powers. But that which is a means must always be a means for something and somewhere along the line there must be a final end or goal which has value in itself. This is what Aristotle finds in the development of man's intellectual capacities. Wisdom is not only a virtue but it stands highest among all the virtues. It is the realization of a capacity which distinguishes man from the lower animals and gives to him a kind of kinship with the gods. The fact that wisdom is an end in itself does not mean that it is useless for anything else. It can be used to direct life's activities but it also has a positive value in addition to this use, for it is in contemplation that man finds his greatest happiness and the fulfillment of that which is unique in his nature.
