There's an interesting dispute just started on Wikipedia concerning whether it is reasonable to see some commonality of meaning between the concept of proof in mathematics and in other areas such as rhetoric, law, philosophy, religion, science, etc. The dispute is at one or both of http://en.wikipedia.org/wiki/Talk:Proof_(informal)#Disambig_page (Editors keep changing the name of the article, which was Proof (truth) when I wrote it and others have replaced "truth" first by "logic" and then by "informal", neither of which are an improvement.) The origin of the article in dispute is as follows. Some months ago I went to Wikipedia to look up what it considered to be a proof and found only a dab (disambiguation) page listing ten articles that seemed to about proof as applied to propositions and about as many more to do with testing and quality control as in galley proof, proof spirit, etc. It seemed to me that the former kind were not so much different meanings of the notion of proof as the same meaning arising in different areas all depending on that meaning. So, still some months ago, I wrote an article on that common notion which began "A proof is sufficient evidence for the truth of a proposition," which as it happens is essentially the first entry in the definition at dictionary.com. The article enumerated the various notions of proof arising in different disciplines (all of which have their own Wikipedia articles with much more detail), and made a start on characterizing the scope of "evidence" (need not be verbal, and need not contain the asserted proposition) and "sufficient" (strict for formal proofs, less so elsewhere, to different degrees). The main dispute at the moment is Gandalf61's insistence that "Proof in mathematics is not based on 'sufficient evidence' - it is based on logical deductions from axioms. It is an entirely different concept from proof in rhetoric, law and philospohy." He backs this up with quotes from Krantz---"The unique feature that sets mathematics apart from other sciences, from philosophy, and indeed from all other forms of intellectual discourse, is the use of rigorous proof" and Bornat---"Mathematical truths, if they exist, aren't a matter of experience. Our only access to them is through reasoned argument." My position is that logical and mathematical proofs differ from proofs in other disciplines in the provenance of their evidence and the rigor of their arguments as parametrized by "sufficient." Whereas evidence in mathematics is drawn from the mathematical world, evidence in science is drawn from our experience of nature. And whereas formal logic sets the sufficiency bar very high, mathematics sets it lower and other disciplines lower still, at least according to the conventional wisdom. Whereas I find my position in complete accord with the quotes of both Krantz and Bornat when interpreted as in the preceding paragraph, Gandalf61 does not. My questions are 1. Is mathematical proof so different from say legal proof that the two notions should be listed on a disambiguation page as being unrelated meanings of the same word, or should they be treated as essentially the same notion modulo provenance of evidence and strictness of sufficiency, both falling under the definition "sufficient evidence of the truth of a proposition." 2. Gandalf61 evidently feels his sources, Krantz and Bornat, prove the notions are incomparable. Are there suitable sources for the opposite assertion, that they are comparable? 3. Someone with a very heavy hand has tagged practically every sentence with a "citation needed" tag. For those that genuinely do need a source, what would you recommend? Vaughan Pratt PS. I hope this sort of argument doesn't put anyone off volunteering to help out on Wikipedia. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]