Newton's great generalization, which he called the "third law of motion," was that "Action and reaction are always equal to each other;" and that law has been one of the most pregnant of all truths about the mystery of force;--one of the brightest windows through which modern eyes have looked into the world of Nature.
Phillips BrooksOnly the soul that with an overwhelming impulse and a perfect trust gives itself up forever to the life of other men, finds the delight and peace which such complete self-surrender has to give.
Phillips Brooks