“The advantage, the luxury, as well as the torment and responsibility of the novelist, is that there is no limit to what he may attempt as an executant — no limit to his possible experiments, efforts, discoveries, successes.”

A Collection of Essays, pp. 65-66
Charles Dickens (1939)

Source: Ghost in the Shell

Source: The Journey Home (1977), p. 121
Context: As for the "solitary confinement of the mind," my theory is that solipsism, like other absurdities of the professional philosopher, is a product of too much time wasted in library stacks between the covers of a book, in smoke-filled coffeehouses (bad for brains) and conversation-clogged seminars. To refute the solipsist or the metaphysical idealist all that you have to do is take him out and throw a rock at his head: if he ducks he's a liar. His logic may be airtight but his argument, far from revealing the delusions of living experience, only exposes the limitations of logic.

Knowing Yourself: The True in the False (1996)
Context: You think: you become that thought. And consciousness, or the state of pure awareness, is lost. The highest knowledge man can possess is that which is true in his own experience. If his experience is limited, so is his knowledge and he behaves accordingly.

The Evolution of Physics (1938) (co-written with Leopold Infeld) <!-- later published by Simon & Schuster (1967) -->
1930s
Context: Physical concepts are free creations of the human mind, and are not, however it may seem, uniquely determined by the external world. In our endeavor to understand reality we are somewhat like a man trying to understand the mechanism of a closed watch. He sees the face and the moving hands, even hears its ticking, but he has no way of opening the case. If he is ingenious he may form some picture of a mechanism which could be responsible for all the things he observes, but he may never be quite sure his picture is the only one which could explain his observations. He will never be able to compare his picture with the real mechanism and he cannot even imagine the possibility or the meaning of such a comparison. But he certainly believes that, as his knowledge increases, his picture of reality will become simpler and simpler and will explain a wider and wider range of his sensuous impressions. He may also believe in the existence of the ideal limit of knowledge and that it is approached by the human mind. He may call this ideal limit the objective truth.

1960, Speech to the Greater Houston Ministerial Association

Variant translation: Believe me that he who has passed his time in retirement, has lived to a good end, and it behoves every man to live within his means
III, iv, 26
Tristia (Sorrows)

Source: The Great Hunt