From page 3 of the first (1891) edition of Charles Darwin’s The Descent of Man:

It has often and confidently been asserted, that man’s origin can never be known: but ignorance more frequently begets confidence than does knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science.

Commentary: This is not “scientism”, as anti-rationalists are likely to claim. Darwin is not saying that science will solve everything, but that most claims that specific problems are beyond science are rooted in ignorance. Darwin, of course, was writing before the age of Gödel, Turing, and other explorers of the limits of rationality. Today we can confidently assert that certain problems are not within the power of science and logic to resolve. But Darwin’s claim still stands. When I see people lamenting “scientism” and demanding that science acknowledge its limits, they are almost never working from a position of informed knowledge about the Halting Problem, the Incompleteness Theorem, or a robust understanding of quantum uncertainty. In virtually every case, they are not really arguing about the limits of science, but digging up reasons to explain why their personal beliefs should not be modified according to what science really can tell us about the world.