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nd candor worthy of a better value of [pi]. Mr. Smith's method of proving that every circle is 3-1/8 diameters is to assume that it is so,--"if you dislike the term datum, then, by hypothesis, let 8 circumferences be exactly equal to 25 diameters,"--and then to show that every other supposition is thereby made absurd. The right to this assumption is enforced in the "Nut" by the following analogy: "I think you (!) will not dare (!) to dispute my right to this hypothesis, when I can prove by means of it that every other value of [pi] will lead to the grossest absurdities; unless indeed, you are prepared to dispute the right of Euclid to adopt a false line hypothetically for the purpose {118} of a '_reductio ad absurdum_'[216] demonstration, in pure geometry." Euclid assumes what he wants to _disprove_, and shows that his _assumption_ leads to absurdity, and so _upsets itself_. Mr. Smith assumes what he wants to _prove_, and shows that _his_ assumption makes _other propositions_ lead to absurdity. This is enough for all who can reason. Mr. James Smith cannot be argued with; he has the whip-hand of all the thinkers in the world. Montucla would have said of Mr. Smith what he said of the gentleman who squared his circle by giving 50 and 49 the same square root, _Il a perdu le droit d'etre frappe de l'evidence_.[217] It is Mr. Smith's habit, when he finds a conclusion agreeing with its own assumption, to regard that agreement as proof of the assumption. The following is the "piece of information" which will settle me, if I be honest. Assuming [pi] to be 3-1/8, he finds out by working instance after instance that the mean proportional between one-fifth of the area and one-fifth of eight is the radius. That is, if [pi] = 25/8, sqrt(([pi]r^2)/5 . 8/5) = r. This "remarkable general principle" may fail to establish Mr. Smith's quadrature, even in an honest mind, if that mind should happen to know that, a and b being any two numbers whatever, we need only assume-- [pi] = a^2/b, to get at sqrt(([pi]r^2)/a . b/a) = r. We naturally ask what sort of glimmer can Mr. Smith have of the subject which he professes to treat? On this point he has given satisfactory information. I had mentioned the old problem of finding two mean proportionals, {119} as a preliminary to the duplication of the cube. On this mention Mr. Smith writes as follows. I put a few words in capitals; and I write rq[218] for the sign of the square ro
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