He needed sun and soil and wind to remain a man. - Clifford D. Simak

As he looked, Sutton felt the cold hand of loneliness reach down with icy fingers to take him in its grip. For here was sheer, mad loneliness such as he had never dreamed. Here was the very negation of life and motion, here was the stark, bald beginning when there was no life, nor even thought of life. Here anything that knew or thought or moved was an alien thing, a disease, a cancer on the face of nothingness.

And I think he actually believes the best way to do it is to gain a dictatorship over the Solar System. That ambition rules everything in his life. It has hardened him and strengthened him. He will crush ruthlessly, without a single qualm, anything that stands in his path. That’s why we’ll have a fight on our hands.

—Look, said Jason, it is an old idea. There was never any proof. There was only faith. I have a soul, one would tell himself. He believed it because he had been told by others. Told authoritatively. Without any question. He was told so often and he told himself so often that there was no question in his mind that he had a soul. But there was never any evidence. There was never any proof.