Hume, David. An Enquiry concerning Human Understanding, Forgotten Books, 1984, pp. 82, 86; first published in 1748 as Philosophical enquiries concerning human Understanding, (or the Oxford 1894 edition OL 7067396M at para. 91) "A wise man ... proportions his belief to the evidence. ... That no testimony is sufficient to establish a miracle, unless the testimony be of such a kind, that its falsehood would be more miraculous, than the fact, which it endeavours to establish; and even in that case there is a mutual destruction of arguments, and the superior only gives us an assurance suitable to that degree of force, which remains, after deducting the inferior." In the 18th century, Pierre-Simon Laplace reformulated the idea as "The weight of evidence for an extraordinary claim must be proportioned to its strangeness." Marcello Truzzi recast it again, in 1978, as "An extraordinary claim requires extraordinary proof." Carl Sagan, finally, popularized the concept broadly as "Extraordinary claims require extraordinary evidence" in 1980 on Cosmos: A Personal Voyage; this was the formulation originally used on Wikipedia.