He who fights with monsters should be careful lest he thereby become a monster. And if thou gaze long into an abyss, the abyss will also gaze into thee.
The distance, and as it were the space around man, grows with the strength of his intellectual vision and insight: his world becomes profounder; new stars, new enigmas, and notions are ever coming into view. Perhaps everything on which the intellectual eye has exercised its acuteness and profundity has just been an occasion for its exercise, something of a game, something for children and childish minds