Everything that I know directly is part of my "mind," and the inferences by which I arrive at the existence of other things are by no means conclusive. It may be, therefore, that nothing exists except my mind. In that case, when I die the universe will go out. But if I am going to admit minds other than my own, I must admit the whole astronomical universe, since the evidence is exactly equally strong in both cases.
Source: Religion and Science, 1935, chapt. 8
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