The unfortunate carelessness of Tennemann and Hamilton has engendered a very serious philosophic corruption. For, it has turned a sound rule of Methodology into a Metaphysical dogma. As J.S. Mill pointed out in his Examination of Hamilton (ch. 24, p. 542 in 4th edition): "The Law of Parcimony ... is a purely logical precept". It is folly, to complicate research by multiplying the objects of inquiry; but we know too little of the ultimate constitution of the Universe, to assume that it cannot be far more complex than it seems, or than we have any actual reason to sup-
pose. The value of this warning has just now received signal illustration from the very recent discovery of Chemical Isotopes; which has proved (e.g.), that what had previously been simply called "lead" is infinitely complex in its composition.[1] This discovery ought to operate as a salutary check upon dogmatism, and the tendency to turn logical rules into ontological principles.
Appendix
Some readers of Mind, and other students of Philosophy, to whom the rare works of Ockham are not readily accessible, may be glad to have the following list of seventeen relevant quotations at hand for ready reference: -
A. "Pluralitas non est ponenda sine necessitate." (1) In Sententias (Petri Lombardi), lib. i., Distinctio i., QQ. 1 and 2. (2) In SS., i., D. 7, Q. 2. (3) Quodlibeta, i., Q. 3. (4) Do., iii., Q. 2. (5) Do., iv., Q. 15. (6) Do., v., Q. 5 (lines 3 and 4).
B. "Non est ponenda pluralitas sine necessitate." In SS., ii., Q. 15 (second column): Utrum Angelus superior intelligat per pauciores species quam inferior?
C. "Nunquam ponenda est pluralitas sine necessitate." In SS., i., D. 27, Q. 2 (section K, not J as given by Prantl in his Note 758). The matter discussed is Species Intelligibilis.
D. "Talis species (intelligibus) non est ponenda propter superfluitatem." Expositio Aurea: Perierm., Proem. See Prantl, N. 757.
E. "Si duae res sufficiunt ad ejus veritatem, superfluum est ponere aliam (tertiam) rem": (1) Quodlibeta, iv., Q. 19; (Prantl, N. 768). (2) Do., iv., Q. 24; (Haureau, ii., 459).
F. "Sufficiunt singularia, et ita tales res universales omnino frustra ponuntur." In SS., i., D. 2, Q. 4 (top of column 18).
G. "Frustra fit per plura, quod potest fieri per pauciora."
- (1) Summa Tot. Log., Pars. i., cap. 12, f. 6, r. A.: referring to Intentio prima and secunda.
- (2) In SS., i., D. 31, Q. 1 (middle of first column): Utrum Identitas, Similitudo, et Equalitas in divinis sint relationes reales?
- (3) In SS., ii., Q. 15, sections O and Q: referring to Species Intelligibilis.
