A man who makes assertions, or draws conclusions, regarding any given case, ought to be competent to investigate it. He has no right to throw the onus on others, declaring it their duty to prove him right or wrong. His duty is to demonstrate the truth of that which he asserts, or to cease from asserting.

Experimental Researches in Chemistry and Physics, Lecture on Mental Education (p. 486), Richard Taylor & William Francis. 1859