Loneliness is emptiness; and moral nature has as much horror of it as physical nature. Solitude is habitable only for the man of genius who fills it with his ideas - daughters of the spiritual world - or for the beholder of divine works who finds it illuminated by the day of heaven, animated by the breath and by the voice of God. Save these two men, so close to paradise, loneliness is to torture what morale is to physique. Between loneliness and torture there is all the difference between nervous illness and surgical illness. It is suffering multiplied by infinity. The body touches infinity through the nervous system, just as the mind enters it through thought.