APPENDIX B 



upon ; the male suppl3dng the apx^ of " movement," 

 the female supplying the material. It is Bpe-miicr) iftyxq 

 which is the source of this movement (just as in the 

 other case it was SpeKTiKT) tlwyq which was the source of 

 the movement) — it brings about both generation and 

 growth, for dperrTiKT] ijwxff and yewrp-iKTj ipv^rj are one 

 and the same (see 735 a 17, 18). And the " organs " 

 or " instruments " which it uses are heat and cold : its 

 movement is " in " them. (This last sentence serves to 

 emphasize the dual nature of SIl, dealt with in §§ 20 ff. 

 below ; for of course SII is the primary " instrument " 



of BpiTTTLKT} </(U;^.) 



[Further important statements on these subjects are 

 found in Meteor. IV. Hot substance and cold sub- 

 stance, says Aristotle, are " active " (because they bring 

 things together, are avyKpiTiKa), solid substance and 

 fluid substance are " passive." Tevems, i.e., natural 

 change, is the work of these dynameis ; so is natural 

 {koto, ^vaiv) (f>6opd ; these processes occur in plants, 

 animals, and their parts, and are brought about by hot 

 and cold substance, when those ex'^ai Xoyov (cf. G.A. 

 m b 28), out of the substrate matter underlying each 

 natural thing, viz., out of the " passive " dynameis. If 

 hot and cold fail to gain the mastery over the matter, 

 anei/iia results. Apart from destruction by force, the 

 end of all natural objects is putrefaction : it may be 

 defined as the Sdopd of the proper and natural {Kara 

 <f>vaiv) heat in any fluid thing by the agency of alien 

 heat (that of the environment), due to lack of proper 

 heat, i.e., owing to cold ; hence hot and cold are the 

 causes of putrefaction as they are of yeveais. Animals 

 are generated in putrefying substances because the 

 heat that was secreted in these substances is natural 

 and is able auviardvai (see Introd. § 54). Cf. the whole 

 Book, especially 390 b 2 flF.] 

 (12) G.A. II. 743 a 20. It is not any chance material which Requisites 

 gets made into flesh or bone, nor does it get made in any ^9'' forma- 

 chance manner or at any chance time, but only the gj^biro. 

 material ordained by Nature, and in the manner and at 

 the time ordained by Nature : that which is potentially 

 X will not be made, actualized, into X by any motive 

 agent other than one which possesses the actuality ; nor 



581 



