[14] Lucretius, De rerum natura, translated by W. H. D. Rouse, Loeb Classical Library, London, 1924, bk. VI, lines 998-1041.
[15] Galen, On the natural faculties, translated by A. S. Brock, Loeb Classical Library, London, 1916, bk. 1 and bk. 3. A view similar to this appeared in Plato, Timaeus, 81 (see [footnote 13]).
[16] This same concept was to reappear in the Middle Ages as the inclinatio ad simile.
[17] The background for much of the following was derived from Annaliese Maier, An der Grenze von Scholastik und Naturwissenchaft, ed 2, Rome, 1952.
[18] St. Thomas' epistemology for the natural inanimate world was based upon Aristotle's dictum: that which is in the mind was in the senses first.
[19] René Descartes, Oeuvres, Charles Adam and Paul Tannery, Paris, 1897-1910, vol. 2, p. 597 (letter to Mersenne, 16 Oct., 1639), and vol. 11 (Le Monde), p. 39. The original definition can be found in Aristotle, Physics, translated by P. H. Wickstead and F. M. Cornford, Loeb Classical Library, London, 1934, 201a10. Aquinas rephrases the definition as "Motus est actus existentis in potentia secundum quod huius modi." See St. Thomas Aquinas, Opera omnia, Antwerp, 1612, vol. 2, Physicorum Aristotelis expositio, lib. 3, lect. 2, cap. a, p. 29.
[20] St. Thomas Aquinas, op. cit. ([footnote 19]), vol. 9, Summa contra gentiles, lib. 3, cap. 92 (Quo modo dicitur aliquis bene fortunatus et quo modo adjuvatur homo ex superioribus causis), p. 343.
[21] St. Thomas Aquinas, op. cit. ([footnote 19]), vol. 17 Opuscula, De operationibus occultis naturae ad queindam militem ultramontem, pp. 213-224.
[22] St. Thomas Aquinas, op. cit. ([footnote 19]), vol 7, Scriptum in quartum librum sententiarum magistri Petri Lombardi, lib. 4, disq. 33 (De diversis coniugii legibus), art. 1 (Utrum habere plures uxores sit contra legem naturae), p. 168. The same statement occurs in one of his most mature works, op. cit. vol. 20, Summa theologica, pars 3 (supplementum), quaestio 65 (De pluralitate uxorum in quinque articulos divisa), art. 1 (Utrum habere plures uxores sit contra legem naturae), p. 107.
[23] St. Thomas Aquinas, op. cit. ([footnote 19]), vol. 8, Quaestio unica: de spiritualibus creaturis, art. 2 (Utrum substantia spiritualis possit uniri corpori), p. 404. See also vol. 9, Summa contra gentiles, lib. 3, cap. 92 (Quomodo dicitur aliquis bene fortunatus, et quomodo adjuvatur homo ex superioribus causis), p. 344; and vol. 17, Opuscula, De operationibus occultis naturae ad queindam militem ultramontem, pp. 213-214.