is to distinguish the physical sequences of molecular motion, which the physical sciences articulate, from the Power with which metaphysics and theology are concerned, and which we approach through consciousness.
974 Having, in the preceding sections, contrasted perceived motions and their immanent originating Power—matter and mind—physics and metaphysics—he proceeds in this and the seven following sections to explain more fully what ha means by _principium_ and also the two meanings (metaphysical and mechanical) of _solutio_. By _principium_, in philosophy, he understands universally efficient supersensible Power. In natural philosophy the term is applied to the orderly sequences manifested to our senses, not to the active cause of the order.
975 “ratiocinio...redditæ universales.” Relations of the data of sense to universalising reason are here recognised.
976 “natura motus.” Sect. 43-66 treat of the nature of the _effect_—i.e.
perceptible motion, as distinguished from its true causal origin (_principium_) in mind or spirit. The origin of motion belongs to metaphysics; its nature, as dependent on percipient experience, belongs to physics. Is motion independent of a plurality of bodies; or does it involve bodies in relation to other bodies, so that absolute motion is meaningless? Cf. _Principles_, sect. 111-116.
977 “idea illa tenuissima et subtilissima.” The difficulty as to definition of motion is attributed to abstractions, and the inclination of the scholastic mind to prefer these to concrete experience.
978 Motion is thus defined by Aristotle:—Διὸ ἡ κίνησις ἐντελέχεια τοῦ κινητοῦ, ᾗ κινητόν. Nat. Ausc. III. ii; see also i. and iii. Cf.
Derodon, _Physica_, I. ix.
979 Newton.
980 Cf. sect. 3-42.
1.
983 Καὶ διὰ τοῦτο δὴ χαλεπὸν αὐτὴν λαβεῖν τί ἐστίν. _Nat. Ausc._ III.
ii.
984 e.g. Zeno, in his noted argument against the possibility of motion, referred to as a signal example of fallacy.
985 “de infinite, &c.” Cf. _Principles_, sect. 130-132, and the _Analyst_ passim, for Berkeley’s treatment of infinitesimals.
986 “confundere.” Cf. sect. 3-42 for illustrations of this confusion.
987 The modern conception of the “conservation of force.”
988 Aristotle states the question in _Nat. Ausc._ VIII. cap. i, and solves it in cap. iv.
989 “mutatio loci” is the effect, i.e. motion perceived by sense; “vitale principium” the real cause, i.e. vital rational agency.
991 “motum localem.” Sect. 52-65 discuss the reality of absolute or empty space, in contrast with concrete space realised in perception of the local relations of bodies. The meaninglessness of absolute space and motion is argued. Cf. _Principles_, sect. 116, 117. See Locke’s _Essay_, Bk. II. ch. 13, 15, 17; also _Papers which passed between Mr. Leibnitz and Dr. Clarke in 1715-16_, pp. 55-59; 73-81; 97-103, &c. Leibniz calls absolute space “an ideal of some modern Englishman.”
992 Newton’s _Principia_, Def. Sch. III. See also Derodon, _Physica_, P.
I. cap. vi. § 1.
993 Cf. Locke on a vacuum, and the “possibility of space existing without matter,” _Essay_, Bk. II. ch. 13.
994 Note the account here given of _imagination_ and _intellect_, as distinguished from _sense_, which may be compared with αἴσθησις, φαντασία, and νοῦς in Aristotelian psychology.
995 “attributorum divinorum particeps.” See Samuel Clarke, in his _Demonstration_, and in the _Papers between Clarke and Leibnitz_.
996 “nostrum,” sc. corpus. When we imagine space emptied of bodies, we are apt to forget that our own bodies are part of the material world.
997 [Vide quæ contra spatium absolutum disseruntur in libro _De Principiis Cognitionis Humanæ_, idiomate anglicano decem abhine annis edito.]—AUTHOR. He refers to sect. 116 of the _Principles_.
998 He treats absolute space as nothing, and relative space as dependent on Perception and Will.
1000 See Locke, _Essay_, Bk. II. ch. 13, §§ 7-10.
1001 Sect. 67-72 treat of the supposed ejection of motion from the striking body into the body struck. Is this only metaphorical? Is the motion received by the latter to be supposed identical with, or equivalent to, that given forth by the former?
_ 1004 De Vi Percussionis_, cap. IX.
1005 Newton’s third law of motion.
1006 Berkeley sees in motion only a link in the chain which connects the sensible and intelligible worlds—a conception unfolded in his _Siris_, more than twenty years later.
1007 “provincia sua.” The _De Motu_, so far as it treats of motion perceptible to the senses, is assigned to physics; in contrast to theology or metaphysics, alone concerned with active causation.