C. S. Peirce Manuscripts

{Left margin, top of page: "Logic 11"}

the extremely loose reasoning of all the philosophers. It was a matter open to the remark of every mathematician, even before Weierstrass {Refers to Karl Theodor Wilhelm Weierstrass (1815-1897).}, when mathematical reasoning was far less strict than it has since become. the more recent philosophers show no improvement in this respect. You may search the whole library of modern metaphysics from Descartes to Royce and hardly find a single argument which does not leave room to drive a coach through it, commodiously. The effect upon the minds of those who have been nourished on such food mainly becomes deplorably patent to everybody who finds himself in contact with them. Their natural sense of logic is enfeebled and diseased. I am confident I detect something of this even in the majority of those young men who become known me only as having paid particular attention to philosophy