ARISTOTLE 



640 a ^ 



avayKTjs iorlv ri earat. ouS' eariv els aihiov ovv 

 aprrjaai rrjg rotavT'qs aTTohei^eats ttjv dvdyKrjv, 

 iooT etVetv, eVet rdS' iarlv, on rdS' eoriv. 8t- 

 wpiarai Se kol Trepl tovtojv iv irepois, koI ttolols 

 V7Tap)(^€L KOI TToZa dvTLUTpe(f)eL Kal Sta rtV alriav. 



10 Aet 8e /XT^ XeXrjOevai Kal TTorepov TrpooriqKeL Xeyeiv, 

 ojanep ol irporepov i-noiovvro rrjv decopiav, ttws 

 GKaarov yiveodai 7Te(f)VKe fxdXXov 7) ttojs ecrrtv. 

 ov yap TL jjLiKpov 8ia(f)ep€L rovro eKeivov. €olk€ 

 o ivrevdev dpKreov elvai [Kaddirep Kal rrporepov 

 €L7TOfiev, on TTpdJTov Ta cfyaivofMeva XrjTTreov Trepl 



15 eKaarov yivos, eW^ ovTa> ras" alrias tovtojv 

 XeKTeov) Kal Trepl yeveoeojs' fidXXov yap raSe 

 ovfi^aivei Kal Trepl ttjv olKoS6fji7]GLV eVet rotdvS' 

 ecrrt to elSos ttjs olKias, t] Toiovh" IutIv rj oWia otl 

 yiveTai ovtojs. rj yap yeveois eveKa ttjs ovoias 

 eoTLV, aAA* ovx 'f) ovuia eveKa ttjs yeveGews . StoTrep 



20 'E/XTreSo/cATj? ovK opdcog eiprjKe Xeycov VTrdp^eiv 



TToXXd TOLS ^CpOLS Sid TO GVjJL^TJvai OVTCJS iv TTj 



yeveGei, otov Kal tt^v pd^iv ToiavTiqv ex€LV otl 

 OTpa(f)evTos KaTa^d^jvai Gvve^r], dyvoojv TrpwTov p.ev 



OTl Set TO GTTepfXa to GVVlGTdv^ VTTapX^LV TOLaVTTjV 

 ^ ovviorav Piatt : avarav vulg. 



** Though of course this Necessity has its place in natural 

 science (see 642 a 31 ff.). It is, however, not the only sort 

 of Necessity in Natural science, and not the paramount one. 



* See De gen. et corr. 337 b 25 ff. An example of a non- 

 convertible proposition is : Foundations are necessary for a 

 house to be built. You cannot say, " If foundations are laid 

 a house must of necessity be built," because it is not " ab- 

 solutely " and always necessary that a house should be built. 



' Cf. Plato, Philebus 54 a-c. 

 60 



