4p39d.md (1026B)
1 The human body needs many other bodies for its 2 preservation (II. Post. iv.). But that which constitutes the 3 specific reality (forma) of a human body is, that its parts 4 communicate their several motions one to another in a certain 5 fixed proportion (Def. before Lemma iv. after II. xiii.). 6 Therefore, whatsoever brings about the preservation of the 7 proportion between motion and rest, which the parts of the human 8 body mutually possess, preserves the specific reality of the 9 human body, and consequently renders the human body capable of 10 being affected in many ways and of affecting external bodies in 11 many ways; consequently it is good (by the last Prop.). Again, 12 whatsoever brings about a change in the aforesaid proportion 13 causes the human body to assume another specific character, in 14 other words (see Preface to this Part towards the end, though the 15 point is indeed self–evident), to be destroyed, and consequently 16 totally incapable of being affected in an increased numbers of 17 ways; therefore it is bad. Q.E.D. 18 19