As a rule, the man who first thinks of a new idea is so much ahead of his time that every one thinks him silly, so that he remains obscure and is soon forgotten.
 Bertrand Russell, A History of Western Philosophy (1945). copy citation

Context

“this might have been written in the nineteenth century. In Locke’s theory of government, I repeat, there is little that is original. In this Locke resembles most of the men who have won fame for their ideas. As a rule, the man who first thinks of a new idea is so much ahead of his time that every one thinks him silly, so that he remains obscure and is soon forgotten. Then, gradually, the world becomes ready for the idea, and the man who proclaims it at the fortunate moment gets all the credit. So it was, for example, with Darwin; poor Lord Monboddo was a laughing-stock.” source