If purpose, then, is inherent in art, so is it in Nature also. The best illustration is the case of a man being his own physician, for Nature is like that - agent and patient at once.
- Aristotle
My agent is the quickest, sharpest man on earth.
- Christoph Waltz
Habit is thus the enormous flywheel of society, its most precious conservative agent. It alone is what keeps us all within the bounds of ordinance, and saves the children of fortune from the envious uprisings of the poor.
- William James
I was able to see faith as more than just a comfort to the weary or a hedge against death; rather, it was an active, palpable agent in the world.