Winston Churchill published a surprising essay in March 1942: “Are There Men on the Moon?”:
I am not sufficiently conceited to think that my sun is the only one with a family of planets and, therefore, that our little earth is unique. Once we admit that the other stars probably also have planets, at any rate a goodly proportion of them, it is more than likely that a large fraction of these will be the right size to keep on their surface water and, possibly, an atmosphere of some sort; and, furthermore, at the proper distance from their parent sun, to maintain a suitable temperature. Do they house living creatures, or even plants? The answer to this question may never be known.
“[T]he odds are enormous that there must be immense numbers which possess planets whose circumstances would not render life impossible,” he concluded. “I, for one, am not so immensely impressed by the success we are making of our civilization here that I am prepared to think we are the only spot in this immense universe which contains living, thinking creatures, or that we are the highest type of mental and physical development which has ever appeared in the vast compass of space and time.”
(Winston Churchill, “Are There Men on the Moon?”, Sunday Dispatch, March 8, 1942.)