“one of those men who reach such an acute limited excellence at twenty−one that everything afterward savors of anti−climax.”

“One that desires to excel should endeavour in those things that are in themselves most excellent.”

“Why should a man deliberately encircle his mind with needless prison walls. No man can reach highest excellence who puts limits to his own thought.”

“I'm sure the liars as skillful and persistent and devious as you reach the point where it's the one you are lying to, and not you, who seems like the one with the serious limitations.”

“A geologist should be well versed in chemistry, natural philosophy, mineralogy, zoology, comparative anatomy, botany; in short, in every science relating to organic and inorganic nature. …But the brief duration of human life, and our limited powers, are so far from permitting us to aspire to such extensive acquisitions, that excellence even in one department is within the reach of few, and those individuals most effectually promote the general progress, who concentrate their thoughts on a limited portion of the field of inquiry.”

““… I said about limiting factors. Well, there’s one that you can’t beat. Put steel under fifty thousand pounds per square inch pressure and it starts to flow. The metal used in this machine must have been able to withstand much greater pressure, but there was a limit beyond which it was not safe to go. At twenty miles above the planet’s surface, they had reached that limit. They had reached dead end.” <…>”

“The only thing that separates any one of us from excellence is fear and the opposite of fear is faith. I am careful not to confuse excellence with perfection. Excellence I can reach for, perfection is God’s business.”

“I far excel every one else in the whole world,
of those who still eat bread upon the face of the earth.”

“Agreeable men are those who are interested in everything; men who accomplish things, who finish their tasks, are those who, during a given period of time, interest themselves in one thing only. In America these men are said to possess "single-track minds"' their tenacity and their obsession are sometimes boring, but they succeed, by repeated attacks, in demolishing the obstacles that hinder their progress.”

“A prudent man should always follow in the path trodden by great men and imitate those who are most excellent.”