Everyone who observes himself doubting observes a truth, and about that which he observes he is certain; therefore he is certain about a truth. Everyone therefore who doubts whether truth exists has in himself a truth on which not to doubt.... Hence one who can doubt at all ought not to doubt the existence of truth.
Saint AugustineSomeone who knows enough to become the owner of a tree, and gives thanks to you for the benefits it brings him, is in a better state, even if ignorant of its height in feet and the extent of its spread, than another who measures and counts all its branches but neither owns it nor knows its creator nor loves him.
Saint Augustine