Quote by Thomas Aquinas

“In ends there is found a twofold order, to wit, the order of intention and the order of execution, and in both orders there must be some first point. That which is first in the order of intention is a sort of principle moving the desire: take that principle away, and desire would have nothing to move it. The moving principle of the execution is that from whence the work begins: take away that moving principle, and none would begin to work at anything. Now the moving principle of the intention is the last end: the moving principle of the execution is the first step in the way of means to the end. Thus, then, on neither side is it possible to go on to infinity: because, if there were no last end, nothing would be desired, nor any action have a term, nor would the intention of the [3] agent rest. On the other hand, if there were no first step in the means to the end, no one would begin to work at anything, and deliberation would never terminate, but go on to infinity.”