The principles of science

by William Stanley Jevons

[48] “Velut si dicam, Sol, Sol, Sol, non tres soles effecerim, sed uno toties prædicaverim.”

[49] Book i., Part iv., Section 5.

[50] Laws of Thought, p. 29. It is pointed out in the preface to this Second Edition that Leibnitz was acquainted with the Laws of Simplicity and of Commutativeness.

[51] Prior Analytics, i. cap. xxvii. 3.

[52] Encyclopædia Britannica, Eighth Ed. art. Logic, sect. 37, note. 8vo. reprint, p. 79.

[53] De Morgan, On the Root of any Function. Cambridge Philosophical Transactions, 1867, vol. xi. p. 25.

[54] Syllabus of a proposed System of Logic, §§ 122, 123.

[55] Elementary Lessons in Logic, p. 86.

[56] Outline of the Laws of Thought, § 87.

[57] Treatise on Natural Philosophy, vol. i. p. 161.