On Certainty in 1969. See also Samuel Johnson, who is said to have kicked a rock on learning of Bishop Berkeley's denial of matter, declaring "I refute it thus!" Diogenes, who is said to have walked away upon hearing a philosophical argument denying the existence of motion, intending to prove without utterance that motion does indeed exist. In Leo Tolstoy's War and Peace, determinism is refuted as: “You say: I am not free. But I have raised and lowered my arm. Everyone understands that this illogical answer is an irrefutable proof of freedom.” References External links Kelly, Thomas. "Moorean Facts and Belief Revision, or Can the Skeptic Win?". Princeton University, in John Hawthorne (ed.), Philosophical Perspectives, vol.19: Epistemology, 2005. Skepticism Concepts in epistemology