If therefore among the ends at which our actions aim there be one which we will for its own sake, while we will the others only for the sake of this, and if we do not choose everything for the sake of something else (which would obviously result in a process ad infinitum, so that all desire would be futile and vain), it is clear that this one ultimate End must be the Good, and indeed the Supreme Good.

Will not then a knowledge of this Supreme Good be also of great practical importance for the conduct of life? Will it not better enable us to attain our proper object, like archers having a target to aim at?

If this be so, we ought to make an attempt to determine at all events in outline what exactly this Supreme Good is, and of which of the sciences or faculties it is the object.

Now it would seem that this supreme End must be the object of the most authoritative of the sciences—some science which is pre-eminently a master-craft.

But such is manifestly the science of Politics;