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 BrooksYou may look through the streets of heaven, asking each how they came to b there, and you will look in vain everywhere for a person who is morally and spiritually strong, whose strength did not come to him in struggle. There is no exception anywhere. Every true strength is gained in struggle.
Phillips BrooksThe lives of men who have been always growing are strewed along their whole course with the things they have learned to do without.
Phillips Brooks