“Difficulties break some men but make others. No axe is sharp enough to cut the soul of a sinner who keeps on trying, one armed with the hope that he will rise even in the end.”

Fiction, The Colour Out of Space (1927)
Context: West of Arkham the hills rise wild, and there are valleys with deep woods that no axe has ever cut. There are dark narrow glens where the trees slope fantastically, and where thin brooklets trickle without ever having caught the glint of sunlight. On the gentle slopes there are farms, ancient and rocky, with squat, moss-coated cottages brooding eternally over old New England secrets in the lee of great ledges; but these are all vacant now, the wide chimneys crumbling and the shingled sides bulging perilously beneath low gambrel roofs. The old folk have gone away, and foreigners do not like to live there. French-Canadians have tried it, Italians have tried it, and the Poles have come and departed. It is not because of anything that can be seen or heard or handled, but because of something that is imagined. The place is not good for imagination, and does not bring restful dreams at night.

The Notebooks of Leonardo da Vinci (1883), XX Humorous Writings

in a speech to students at Phillips Exeter Academy, 2007

2010: Odyssey Two (1982), Ch. 43: Thought Experiment
1980s
Context: Plans for the final assault on Big Brother had already been worked out and agreed upon with Mission Control. Leonov would move in slowly, probing at all frequencies, and with steadily increasing power — constantly reporting back to Earth at every moment. When final contact was made, they would try to secure samples by drilling or laser spectroscopy; no one really expected these endeavours to succeed, as even after a decade of study TMA-1 resisted all attempts to analyse its material. The best efforts of human scientists in this direction seemed comparable to those of Stone Age men trying to break through the armour of a bank vault with flint axes.

Orthodoxy (1884)
Context: If Christ wished to convince his fellow-men by miracles, why did he not do something that could not by any means have been a counterfeit? Instead of healing a withered arm, why did he not find some man whose arm had been cut off, and make another grow?

Source: Drenai series, The Swords of Night and Day, Ch. 8
Context: What I did understand from the rebirth process was that the rebirth reproduced a physical duplicate of the original. But this is my point. It is physical. What truly makes a man who he is? Is it the strength of his arms, or the courage of his soul? You have your own soul, Harad. You are not Druss. Live your own life.