Un aforismo de H. G. Wells:
Rest enough for the individual man, too much and too soon, and we call it death. But for man, no rest and no ending. He must go on, conquest beyond conquest. First this little planet and all its winds and ways, and then all the laws of mind and matter that restrain him. Then the planets about him, and, at last, out across immensities to the stars. And when he has conquered all the deep space, and all the mysteries of time, still he will be beginning.