[168] Laws of Thought, pp. 368–375.
[169] De Morgan’s Essay on Probabilities, Cabinet Cyclopædia, p. 67.
[170] Essay on Probabilities, p. 128.
[171] J. S. Mill, System of Logic, 5th edition, bk. iii. chap. xviii. § 3.
[172] Todhunter’s History, pp. 472, 598.
[173] Todhunter’s History, pp. 378, 379.
[174] Philosophical Transactions, [1763], vol. liii. p. 370, and [1764], vol. liv. p. 296. Todhunter, pp. 294–300.
[175] Newton’s Opticks, Bk. I., Part ii. Prop. 3; Nature, vol. i. p. 286.
[176] Aristotle’s Metaphysics, xiii. 6. 3.
[177] Possunt autem omnes testes et uno annulo signare testamentum Quid enim si septem annuli una sculptura fuerint, secundum quod Pomponio visum est?—Justinian, ii. tit. x. 5.