… is from page 66 of the late Stephen Jay Gould’s 1980 collection, The Panda’s Thumb; specifically, it’s from Gould’s December 1979 Natural History essay “Darwin’s Middle Road” – an essay in which Gould argues that Adam Smith’s explanation of the operation of the invisible hand in markets was a chief spark for Charles Darwin’s theory of natural selection:
In fact, I believe that the theory of natural selection should be viewed as an extended analogy – whether conscious or unconscious on Darwin’s part I do not know – to the laissez faire economics of Adam Smith.
Nearly ten years ago I wrote more about this essay by Gould.