_I answer that,_ Man must, of necessity, desire all, whatsoever he
desires, for the last end. This is evident for two reasons. First,
because whatever man desires, he desires it under the aspect of good.
And if he desire it, not as his perfect good, which is the last end,
he must, of necessity, desire it as tending to the perfect good,
because the beginning of anything is always ordained to its
completion; as is clearly the case in effects both of nature and of
art. Wherefore every beginning of perfection is ordained to complete
perfection which is achieved through the last end. Secondly, because
the last end stands in the same relation in moving the appetite, as
the first mover in other movements. Now it is clear that secondary
moving causes do not move save inasmuch as they are moved by the first
mover. Therefore secondary objects of the appetite do not move the
appetite, except as ordained to the first object of the appetite,
which is the last end.

Reply Obj. 1: Actions done jestingly are not directed to any external
end; but merely to the good of the jester, in so far as they afford
him pleasure or relaxation. But man's consummate good is his last end.

Reply Obj. 2: The same applies to speculative science; which is
desired as the scientist's good, included in complete and perfect
good, which is the ultimate end.

Reply Obj. 3: One need not always be thinking of the last end,
whenever one desires or does something: but the virtue of the first
intention, which was in respect of the last end, remains in every
desire directed to any object whatever, even though one's thoughts be
not actually directed to the last end. Thus while walking along the
road one needs not to be thinking of the end at every step.