“The tools of the academic designer are a piece of paper and a pencil with an eraser. If a mistake is made, it can always be erased and changed. If the practical-reactor designer errs, he wears the mistake around his neck; it cannot be erased. Everyone sees it.”

“A fool is someone whose pencil wears out before its eraser does.”

“Do not erase the designs the child makes in the soft wax of his inner life.”

“Write your plans in pencil and give God the eraser.”

“When I erase a word with a pencil, where does it go?”

“The academic-reactor designer is a dilettante. He has not had to assume any real responsibility in connection with his projects. He is free to luxuriate in elegant ideas, the practical shortcomings of which can be relegated to the category of "mere technical details." The practical-reactor designer must live with these same technical details. Although recalcitrant and awkward, they must be solved and cannot be put off until tomorrow. Their solution requires manpower, time and money.”

“The man who has never made a mistake has no need of an eraser; just so the man who has never done anything wrong has no need of a Redeemer.”

“You can hide memories, but you can’t erase the history that produced them.” Sara looked directly into his eyes. “If nothing else, you need to remember that. You can’t erase history, or change it. It would be like destroying yourself.”

“I have rewritten — often several times — every word I have ever published. My pencils outlast their erasers.”

“History cannot be erased or altered. Because that would mean killing yourself.”