Siquidem Newtonus(1002) ait vim impressam consistere in actione sola, esseque actionem exercitam in corpus ad statum ejus mutandum, nee post actionem manere. Torricellius(1003) c.u.mulum quendam sive aggregatum virium impressarum per percussionem in corpus mobile recipi, ibidemque manere atque impetum const.i.tuere contendit. Idem fere Borellus(1004) aliique praedicant. At vero, tametsi inter se pugnare videantur Newtonus et Torricellius, nihilominus, dum singuli sibi consentanea proferunt, res satis commode ab utrisque explicatur. Quippe vires omnes corporibus attributae tam sunt hypotheses mathematicae quam vires attractivae in planetis et sole. Caeterum entia mathematica in rerum natura stabilem essentiam non habent: pendent autem a notione definientis; unde eadem res diversimode explicari potest.
68. Statuamus motum novum in corpore percusso conservari, sive per vim insitam, qua corpus quodlibet perseverat in statu suo vel motus vel quietis uniformis in dir.e.c.t.u.m; sive per vim impressam, durante percussione in corpus percussum receptam ibidemque permanentem; idem erit quoad rem, differentia existente in nominibus tantum. Similiter, ubi mobile percutiens perdit, et percussum acquirit motum, parum refert disputare, utrum motus acquisitus sit idem numero c.u.m motu perdito, ducit enim in minutias metaphysicas et prorsus nominales de ident.i.tate. Itaque sive dicamus motum transire a percutiente in percussum, sive in percusso motum de novo generari, destrui autem in percutiente, res eodem recidit.
Utrobique intelligitur unum corpus motum perdere, alterum acquirere, et praeterea nihil.
69. Mentem, quae agitat et continet universam hancce molem corpoream, estque causa vera efficiens motus, eandem esse, proprie et stricte loquendo, causam communicationis ejusdem haud negaverim. In philosophia tamen physica, causas et solutiones phaenomenon a principiis mechanicis petere oportet. Physice igitur res explicatur non a.s.signando ejus causam vere agentem et incorpoream, sed demonstrando ejus connexionem c.u.m principiis mechanicis: cujusmodi est illud, _actionem et reactionem esse semper contrarias et aequales_(1005), a quo, tanquam fonte et principio primario, eruuntur regulae de motuum communicatione, quae a neotericis, magno scientiarum bono, jam ante repertae sunt et demonstratae.
70. n.o.bis satis fuerit, si innuamus principium illud alio modo declarari potuisse. Nam si vera rerum natura potius quam abstracta mathesis spectetur, videbitur rectius dici, in attractione vel percussione pa.s.sionem corporum, quam actionem, esse utrobique aequalem. Exempli gratia, lapis fune equo alligatus tantum trahitur versus equum, quantum equus versus lapidem: corpus etiam motum in aliud quiescens impactum, pat.i.tur eandem mutationem c.u.m corpore quiescente. Et quoad effectum realem, percutiens est item percussum, percussumque percutiens. Mutatio autem illa est utrobique, tam in corpore equi quam in lapide, tam in moto quam in quiescente, pa.s.sio mera. Esse autem vim, virtutem, aut actionem corpoream talium effectuum vere et proprie causatricem non constat. Corpus motum in quiescens impingitur; loquimur tamen active, dicentes illud hoc impellere: nec absurde in mechanicis, ubi ideae mathematicae potius quam verae rerum naturae spectantur.
71. In physica, sensus et experientia, quae ad effectus apparentes solummodo pertingunt, loc.u.m habent; in mechanica, notiones abstractae mathematicorum admittuntur. In philosophia prima, seu metaphysica, agitur de rebus incorporeis, de causis, veritate, et existentia rerum. Physicus series sive successiones rerum sensibilium contemplatur, quibus legibus connectuntur, et quo ordine, quid praecedit tanquam causa, quid sequitur tanquam effectus, animadvertens.(1006) Atque hac ratione dicimus corpus motum esse causam motus in altero, vel ei motum imprimere, trahere etiam, aut impellere. Quo sensu causae secundae corporeae intelligi debent, nulla ratione habita verae sedis virium, vel potentiarum actric.u.m, aut causae realis cui insunt. Porro dici possunt causae vel principia mechanica, ultra corpus, figuram, motum, etiam axiomata scientiae mechanicae primaria, tanquam causae consequentium spectata.
72. Causae vere activae meditatione tantum et ratiocinio e tenebris erui quibus involvuntur possunt, et aliquatenus cognosci. Spectat autem ad philosophiam primam, seu metaphysicam, de iis agere. Quodsi cuique scientiae provincia sua(1007) tribuatur, limites a.s.signentur, principia et objecta accurate distinguantur, quae ad singulas pertinent, tractare licuerit majore, c.u.m facilitate, tum perspicuitate.
FOOTNOTES
_ 1 Philosophy of Theism_: The Gifford Lectures delivered before the University of Edinburgh in 1894-96. (Second Edition, 1899.)
_ 2 Essay on Vision_, sect. 147, 148.
_ 3 Principles_, sect. 6.
4 Preface to the _Three Dialogues between Hylas and Philonous_.
5 By Anthony Collins.
6 See vol. III, Appendix B.
7 Murdoch Martin, a native of Skye, author of a _Voyage to St. Kilda_ (1698), and a _Description of the Western Islands of Scotland_ (1703).
8 See Stewart"s _Works_ (ed. Hamilton), vol. I. p. 161. There is a version of this story by DeQuincey, in his quaint essay on _Murder considered as one of the Fine Arts._
9 Sir John became Lord Percival in that year.
10 A place more than once visited by Berkeley.
11 Bakewell"s _Memoirs of the Court of Augustus_, vol. II. p. 177.
12 A letter in Berkeley"s _Life and Letters_, p. 93, which led me to a different opinion, I have now reason to believe was not written by him, nor was it written in 1721. The research of Dr. Lorenz, confirmed by internal evidence, shews that it was written in October, 1684, before Berkeley the philosopher was born, and when the Duke of Ormond was Lord Lieutenant of Ireland. The writer was probably the Hon. and Rev. George Berkeley, a Prebendary of Westminster in 1687, who died in 1694. The wife of the "pious Robert Nelson" was a daughter of Earl Berkeley, and this "George" was her younger brother.
13 Percival MSS.
14 For the letter, see Editor"s Preface to the _Proposal for a College in Bermuda_, vol. IV. pp. 343-44.
15 Afterwards Sir John James.
16 Smibert the artist, who made a picture of Berkeley in 1725, and afterwards in America of the family party then at Gravesend.
_ 17 Historical Register_, vol. XIII, p. 289 (1728).
_ 18 New England Weekly Courier_, Feb. 3, 1729.
19 For valuable information about Rhode Island, reproduced in _Berkeley"s Life and Correspondence_ and here, I am indebted to Colonel Higginson, to whom I desire to make this tardy but grateful acknowledgement.
20 James, Dalton, and Smibert.
21 Whitehall, having fallen into decay, has been lately restored by the pious efforts of Mrs. Livingston Mason, in concert with the Rev. Dr.
E. E. Hale, and others. This good work was completed in the summer of 1900; and the house is now as nearly as possible in the state in which Berkeley left it.
22 See vol. III, Appendix C.
_ 23 Three Men of Letters_, by Moses Coit Tyler (New York, 1895). He records some of the American academical and other inst.i.tutions that are directly or indirectly, due to Berkeley.
24 The thought implied in this paragraph is pursued in my _Philosophy of Theism_, in which the ethical perfection of the Universal Mind is taken as the fundamental postulate in all human experience. If the Universal Mind is not ethically perfect, the universe (including our spiritual const.i.tution) is radically untrustworthy.
_ 25 Life and Letters of Berkeley_, p. 222.
26 The third Earl of Shaftesbury, the pupil of Locke, and author of the _Characteristics_. In addition to the well-known biography by Dr.
Fowler, the present eminent Vice-Chancellor of Oxford, Shaftesbury has been interpreted in two other lately published works-a _Life_ by Benjamin Rand, Ph.D. (1900), and an edition of the _Characteristics_, with an Introduction and Notes, by John M.
Robertson (1900).
27 The t.i.tle of this book is-_Things Divine and Supernatural conceived by a.n.a.logy with Things Natural and Human_, by the Author of _The Procedure, Extent and Limits of the Human Understanding_. The _Divine a.n.a.logy_ appeared in 1733, and the _Procedure_ in 1728.
28 Spinoza argues that what is _called_ "understanding" and "will" in G.o.d, has no more in common with human understanding and will than the dog-star in the heavens has with the animal we call a dog. See Spinoza"s _Ethica_, I. 17, _Scholium_.
29 The question of the knowableness of G.o.d, or Omnipotent Moral Perfection in the concrete, enters into recent philosophical and theological discussion in Britain. Calderwood, in his _Philosophy of the Infinite_ (1854), was one of the earliest, and not the least acute, of Hamilton"s critics in this matter. The subject is lucidly treated by Professor Andrew Seth (Pringle-Pattison) in his _Lectures on Theism_ (1897) and in a supplement to Calderwood"s _Life_ (1900).
So also Huxley"s _David Hume_ and Professor Iverach"s _Is G.o.d Knowable?_
30 Stewart"s _Works_. vol. I. pp. 350-1.
31 Berkeley MSS. possessed by Archdeacon Rose.
32 Pope"s poetic tribute to Berkeley belongs to this period-
"Even in a bishop I can spy desert; Secker is decent; Rundle has a heart: Manners with candour are to Benson given, To Berkeley-every virtue under heaven."
_Epilogue to the Satires._
Also his satirical tribute to the critics of Berkeley-
"Truth"s sacred fort th" exploded laugh shall win; And c.o.xcombs vanquish Berkeley with a grin."
_Essay on Satire, _Part II.
33 Berkeley"s _Life and Letters_, p. 210.