8
The quotations in this and the following paragraph are from Thorndike's Educational Psychology, pp. 304-305, Vol. III.
9
Biometrika, Vol. III, p. 156.
10
"William of Occam's Razor" is the canon of logic which declares that it is unwise to seek for several causes of an effect, if a single cause is adequate to account for it.
11
Schuster, Edgar, Eugenics, pp. 150-163, London, 1913.