A Vida de Johnson

Em meio a uma discussão sobre provas e refutações em Filosofia, na aula da semana passada, lembrei de recomendar a um aluno em apuros alguns procedimentos inspirados pelas narrativas de Boswell em "Life of Johnson". Aqui vai o original:
"After we came out of the church, we stood talking for some time together of Bishop Berkeley's ingenious sophistry to prove the non-existance of matter, and that every thing in the universe is merely ideal. I observed, that though we are satisfied his doctrine is not true, it is impossible to refute it. I nevel shall forget the alacrity with Jonhson answered, striking his foot with mighty force against a large stone, till he rebounded from it, "I refut it thus.! This was a stout exemplification of the first truths of Pere Bouffier, or the original principles of Reid and of Beattie; without admitting which, we can no more argue in metaphysicks, than we can argue in mathematics without axioms."
(Life of Samuel Johnson, LL.D, by James Boswell)