“Selfishness is not living as one wishes to live, it is asking others to live as one wishes to live.”

The trial of Charles B. Reynolds for blasphemy (1887)
Context: Gentlemen, you can never make me believe — no statute can ever convince me, that there is any infinite Being in this universe who hates an honest man. It is impossible to satisfy me that there is any God, or can be any God, who holds in abhorrence a soul that has the courage to express his thought. Neither can the whole world convince me that any man should be punished, either in this world or in the next, for being candid with his fellow-men. If you send men to the penitentiary for speaking their thoughts, for endeavoring to enlighten their fellows, then the penitentiary will become a place of honor, and the victim will step from it — not stained, not disgraced, but clad in robes of glory.
Let us take one more step.
What is holy, what is sacred? I reply that human happiness is holy, human rights are holy. The body and soul of man — these are sacred. The liberty of man is of far more importance than any book; the rights of man, more sacred than any religion — than any Scriptures, whether inspired or not.
What we want is the truth, and does any one suppose that all of the truth is confined in one book — that the mysteries of the whole world are explained by one volume?
All that is — all that conveys information to man — all that has been produced by the past — all that now exists — should be considered by an intelligent man. All the known truths of this world — all the philosophy, all the poems, all the pictures, all the statues, all the entrancing music — the prattle of babes, the lullaby of mothers, the words of honest men, the trumpet calls to duty — all these make up the bible of the world — everything that is noble and true and free, you will find in this great book.
If we wish to be true to ourselves, — if we wish to benefit our fellow-men — if we wish to live honorable lives — we will give to every other human being every right that we claim for ourselves.

7
Journey to the End of the Night (1932)

Walden (1854)
Context: I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived. I did not wish to live what was not life, living is so dear; nor did I wish to practise resignation, unless it was quite necessary. I wanted to live deep and suck out all the marrow of life, to live so sturdily and Spartan-like as to put to rout all that was not life, to cut a broad swath and shave close, to drive life into a corner, and reduce it to its lowest terms, and, if it proved to be mean, why then to get the whole and genuine meanness of it, and publish its meanness to the world; or if it were sublime, to know it by experience, and be able to give a true account of it in my next excursion. For most men, it appears to me, are in a strange uncertainty about it, whether it is of the devil or of God, and have somewhat hastily concluded that it is the chief end of man here to "glorify God and enjoy him forever."

"Writing", p. 14
The Dyer's Hand, and Other Essays (1962)

Source: Atlas Shrugged

Epistulae Morales ad Lucilium (Moral Letters to Lucilius), Letter XXX: On conquering the conqueror