My theory of self-made men ...

My theory of self-made men is, then, simply this; that they are men of work. Whether or not such men have acquired material, moral or intellectual excellence, honest labor faithfully, steadily and persistently pursued, is the best, if not the only, explanation of their success... All human experience proves over and over again, that any success which comes through meanness, trickery, fraud and dishonour, is but emptiness and will only be a torment to its possessor.
My theory of self-made men is, then, simply this; that they are men of work. Whether or not such men have acquired material, moral or intellectual excellence, honest labor faithfully, steadily and persistently pursued, is the best, if not the only, explanation of their success... All human experience proves over and over again, that any success which comes through meanness, trickery, fraud and dishonour, is but emptiness and will only be a torment to its possessor.

Quotes from the same author

If there is no struggle, there is no progress.
I prefer to be true to myself, even at the hazard of incurring the ridicule of others, rather than to be false, and to incur my own abhorrence.
No man can put a chain about the ankle of his fellow man without at last finding the other end fastened about his own neck.
What to the Slave is the 4th of July.
A great man, tender of heart, strong of nerve, boundless patience and broadest sympathy, with no motive apart from his country.