Every art and every investigation, and likewise every practical pursuit or undertaking,
seems to aim at some good: hence it has been well said that the Good is That at which all
（It is true that a certain variety
is to be observed among the ends at which the arts and sciences aim: in some cases the
activity of practising the art is itself the end,1
in others the end is some product over and above the mere exercise of the art; and in the
arts whose ends are certain things beside the practice of the arts themselves, these
products are essentially superior in value to the activities.）
But as there are numerous pursuits and arts and sciences, it follows
that their ends are correspondingly numerous: for instance, the end of the science of
medicine is health, that of the art of shipbuilding a vessel, that of strategy victory,
that of domestic economy wealth.
Now in cases where
several such pursuits are subordinate to some single faculty—as bridle-making
and the other trades concerned with horses' harness are subordinate to horsemanship, and
this and every other military pursuit to the science of strategy, and similarly other arts
to different arts again—in all these cases, I say, the ends of the master arts
are things more to be desired than the ends of the arts subordinate to them; since the
latter ends are only pursued for the sake of the former.
（And it makes no difference whether the ends of the pursuits are the activities
themselves or some other thing beside these, as in the case of the sciences
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
, 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?
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;
for it is this that ordains which of the sciences are to exist in