I answer that, Absolutely speaking, it is not possible to proceed indefinitely in the matter of ends, from any point of view. For in whatsoever things there is an essential order of one to another, if the first be removed, those that are ordained to the first, must of necessity be removed also. Wherefore the Philosopher proves (Phys. viii, 5) that we cannot proceed to infinitude in causes of movement, because then there would be no first mover, without which neither can the others move, since they move only through being moved by the first mover. Now there is to be observed a twofold order in ends--the order of intention and the order of execution: and in either of these orders there must be something first. For that which is first in the order of intention, is the principle, as it were, moving the appetite; consequently, if you remove this principle, there will be nothing to move the appetite. On the other hand, the principle in execution is that wherein operation has its beginning; and if this principle be taken away, no one will begin to work. Now the principle in the intention is the last end; while the principle in execution is the first of the things which are ordained to the end. Consequently, on neither side is it possible to go to infinity since if there were no last end, nothing would be desired, nor would any action have its term, nor would the intention of the agent be at rest; while if there is no first thing among those that are ordained to the end, none would begin to work at anything, and counsel would have no term, but would continue indefinitely.