Gnomologia: Adagies and Proverbs; Wise Sentences and Witty Sayings, Ancient and Modern, Foreign and British, Collected by Thomas Fuller, 1732, p. 156
“Everybody is a genius. But, if you judge a fish by its ability to climb a tree, it will spend its whole life believing that it is stupid.”
Often misattributed to Albert Einstein.
Often attributed to Benjamin Franklin, but the earliest occurrence of this quotation was found in a book from 20th century.