It is a paradoxical but profoundly true and important principle of life that the most likely way to reach a goal is to be aiming not at that goal itself but at some more ambitious goal beyond it.
Apathy can be overcome by enthusiasm, and enthusiasm can only be aroused by two things: first, an ideal, with takes the imagination by storm, and second, a definite intelligible plan for carrying that ideal into practice.
The human race's prospects of survival were considerably better when we were defenceless against tigers than they are today when we have become defenceless against ourselves.