[2] Vulgar Errors, book v. chap. 21.
[3] Pharmacologia, Historical Introduction, p. 16.
[4] The author of one of the Bridgewater Treatises has fallen, as it seems to me, into a similar fallacy when, after arguing in rather a curious way to prove that matter may exist without any of the known properties of matter, and may therefore be changeable, he concludes that it cannot be eternal, because "eternal (passive) existence necessarily involves incapability of change." I believe it would be difficult to point out any other connexion between the facts of eternity and unchangeableness, than a strong association between the two ideas. Most of the à priori arguments, both religious and anti-religious, on the origin of things, are fallacies drawn from the same source.
[5] Supra, book ii. chap. v. § 6, and ch. vii. § 1, 2, 3. See also Examination of Sir William Hamilton's Philosophy, chap. vi. and elsewhere.
[6] I quote this passage from Playfair's celebrated Dissertations on the Progress of Mathematical and Physical Science.
[7] This statement I must now correct, as too unqualified. The maxim in question was maintained with full conviction by no less an authority than Sir William Hamilton. See my Examination, chap. xxiv.
[8] Nouveaux Essais sur l'Entendement Humain—Avant-propos. (Œuvres, Paris ed. 1842, vol. i. p. 19.)
[9] This doctrine also was accepted as true, and conclusions were grounded on it, by Sir William Hamilton. See Examination, chap. xxiv.
[10] Not that of Leibnitz, but the principle commonly appealed to under that name by mathematicians.