Montucla, Histoire des Mathématiques, vol. iii. p. 386.

Leibnitz Opera, Dutens’ Edition, vol. vi. part i. p. 217. Todhunter’s History of the Theory of Probability, p. 48. To the latter work I am indebted for many of the statements in the text.

Positive Philosophy, translated by Martineau, vol. ii. p. 120.

System of Logic, bk. iii. chap. 18, 5th Ed. vol. ii. p. 61.

Montucla, Histoire, vol. iii. p. 405; Todhunter, p. 263.

Essay concerning Human Understanding, bk. iv. ch. 14. § 1.

Philosophical Magazine, 4th Series, vol. i. p. 354.

Essay concerning Human Understanding, bk. ii. chap. xxi.

De Rerum Natura, bk. ii. ll. 216–293.

Cambridge Philosophical Transactions (1830), vol. iii. pp. 369–372.

Observations on the Nature and Tendency of the Doctrine of Mr. Hume, concerning the Relation of Cause and Effect. Second ed. p. 44.

Ibid. p. 97.

System of Logic, bk. II. chap, iii.

Inductive Logic, pp. 13, 14.

Bain, Deductive Logic, pp. 208, 209.