Charles Darwin and Alan Turing, in their different ways, both homed in on the same idea: the existence of competence without comprehension.
Some of the greatest, most revolutionary advances in science have been given their initial expression in attractively modest terms, with no fanfare.
Charles Darwin managed to compress his entire theory into a single summary paragraph that a layperson can readily follow.
Francis Crick and James Watson closed their epoch-making paper on the structure of DNA with a single deliciously diffident sentence. ("It has not escaped our notice that the specific pairings we have postulated immediately suggests a possible copying mechanism for the replicating unit of life.")
And Alan Turing created a new world of science and technology, setting the stage for solving one of the most baffling puzzles remaining to science, the mind-body problem, with an even shorter declarative sentence in the middle of his 1936 paper on computable numbers:
It is possible to invent a single machine which can be used to compute any computable sequence.