Unless we act appropriately, methodically, and in line with our nature and constitution, we will fall short of our proper purpose.  Creatures whose constitutions are different have different ends and functions accordingly.  So, for creatures whose constitution is exclusively designed for use, use on its own suffices; but where the capacity to understand that use is added, the creature will only reach its end by bringing the capacity into play.

And so it is inexcusable for man to begin and end where the beasts do.  He should begin where they do, but only end where nature left off dealing with him, which is to say, in contemplation and understanding and a manner of life otherwise adapted to his nature.

Epictetus – Book I:6

“Rise to your higher nature”   -RS Maxims and Stoic’s Toolbox