“They have read your novel... and they said only one thing, that, unfortunately, it is not finished. So I wanted to show you your hero. He has been sitting here for about two thousand years, sleeping, but, when the moon is full, he is tormented, as you see, by insomnia. And it torments not only him, but his faithful guardian, the dog. If it is true that cowardice is the most grave vice, then the dog, at least, is not guilty of it. The only thing that brave creature ever feared was thunderstorms. But what can be done, the one who loves must share the fate of the one who is loved.”

Billie's Blues

Hurry Home, Candy (1953)

Source: One Day in the Life of Ivan Denisovich (1962)

Lt. Col Arthur Freemantle, Part II, CH 5: Longstreet, p. 130
The Killer Angels (1974)

As quoted in "Doom and glory of knowing who you are" by Jane Howard, in LIFE magazine, Vol. 54, No. 21 (24 May 1963), p. 89 https://books.google.com/books?id=mEkEAAAAMBAJ; a part of this statement has often been quoted as it was paraphrased in The New York Times (1 June 1964):
Context: You think your pain and your heartbreak are unprecedented in the history of the world, but then you read. It was Dostoevsky and Dickens who taught me that the things that tormented me most were the very things that connected me with all the people who were alive, or who ever had been alive. Only if we face these open wounds in ourselves can we understand them in other people. An artist is a sort of emotional or spiritual historian. His role is to make you realize the doom and glory of knowing who you are and what you are. He has to tell, because nobody else can tell, what it is like to be alive.

Holmes said, "That was the second great lesson — humility."
Source: Other writings, Felix Frankfurter Reminisces (1960), P. 59.

Highway of Eternity (1986)
Context: He stirred again, halfway between sleep and wakefulness, and he was not alone. Across the fire from him sat, or seemed to sit, a man wrapped in some all-enveloping covering that might have been a cloak, wearing on his head a conical hat that dropped down so far it hid his face. Beside him sat the wolf — the wolf, for Boone was certain that it was the same wolf with which he'd found himself sitting nose to nose when he had wakened the night before. The wolf was smiling at him, and he had never known that a wolf could smile.
He stared at the hat. Who are you? What is this about?
He spoke in his mind, talking to himself, not really to the hat. He had not spoken aloud for fear of startling the wolf.
The Hat replied. It is about the brotherhood of life. Who I am is of no consequence. I am only here to act as an interpreter.
An interpreter for whom?
For the wolf and you.
But the wolf does not talk.
No, he does not talk. But he thinks. He is greatly pleased and puzzled.
Puzzled I can understand. But pleased?
He feels a sameness with you. He senses something in you that reminds him of himself. He puzzles what you are.
In time to come, said Boone, he will be one with us. He will become a dog.
If he knew that, said The Hat, it would not impress him. He thinks now to be one with you. An equal. A dog is not your equal...

Source: Be the Pack Leader: Use Cesar's Way to Transform Your Dog . . . and Your Life