ZENON. Sext. Emp. adv. Math. vii. 228, 230, 236), more exact definitions of which were attempted by Cleanthes, Chrysippus, and others, who deviated the one from the other, showing clearly that none such liad been established by Zenon. In like manner the division of conceptions, or representations ((j>avTa- aiai) into such as were credible (iridavai)., incredible (airidavoi), at once credible and not credible, and Buch as were neither credible nor incredible ; and further into true and false, &c., may very likely have been made by Zenon (Ibid. 242, &c.). It lay at the basis of the subdivision of true conceptions into comprehensible {KaTar}iTriKai i. e. demonstrable, and incomprehensible, which is referred to Zenon. (Cic. Acad. ii. 6, 24.) But here also the more exact definitions are to be ascribed to the later Stoa (Sex. Emp. adv. Math. vii. 253). On the other hand Zenon had reserved for the free-will the power of assent (o-vyKaTcideffis) in distinguish- ing between the impressions communicated to the senses (Cic. Acad. i. 11), and distinguished the following stages : representation, cognition, assent, knowledge, exhibiting their relation to each other by the well-known illustration of the flat-extended hand, and the gradual clenching of the fist (Cic. A cad. ii. 4, i. 1 1 ). As the ultimate criterion of truth Zenon assumed right reason (Diog. Laert. vii. 54, ibid. Interp.), which Chrysippus and others, in turn, endeavoured to separate into its constituent parts. Zenon seems to have had no share, or but very little, in the developement of the Stoic doctrine respecting the categories, conclusions, the parts of speech and rhetoric. The last could have been regarded by him only as an amplification of dialec- tic, according to the comparison referred to by Cicero (Orator. 32), and could hardly have ap- peared to him to need a separate scientific treat- ment. (Cic. de Fin. iv. 3.) It seems that at the head of his Physic stood the proposition that every thing which operates, as well as every thing operated upon, is corporeal, and consequently that the actual is limited to that (Cic. Acad. i. 11). He called the substance, that is to say the basis of every thing existent, that primary matter which neither increases nor dimi- nishes itself (Stob. Eel. Eth. p. 90 ; Diog. Laert. vii. 150). This was in his view the intercommingling of matter, in itself passive and void of quality {&iroiQS vAr/), and of operative power, that is of the deity (Diog. Laert. vii. 134 ; Cic. ^.c; Senec. JE'jow^. 65). He saw this operative power in fire (Cic. Acad. i. 11), or aether (ibid. ii. 41), as the basis of all vital activity (Cic. de Nat. Deor. ii. 9, iii. 14), and in this way was led to go back to the doctrine of Heracleitus. Attaching his views to that doctrine, he taught that the universe comes into being when from fire, or through it, the primary substance passing through the intermediate stage of air, becomes liquefied, and then the thick portion becomes earth, the rarer portion air, and lastly again becomes rarified into fire (Diog. Laert. vii. *142, comp. 136; Stob. Eel. Fhys. p. 320). Zenon also appropriated to himself the Heraclei- tean doctrine of the periodic alternation of the formation and annihilation of the universe (Stob. Eel. Phys. i. p. 414). The more exact definition of the doctrine in this instance also belongs to his successors, as Chrysippus, Poseidonius, &c. The active or artizan-fire (rex^iKhv Trvp, Cic. de Nat. Deor. ii, 22, comp. Diog. Laert. vii. 156) must ZENON. 1315 in his view have been identical with the deity ; but what Heracleitus tacitly pre-supposed, that it partakes of the world-consciousness, Zenon en- deavoured to define more exactly, and to prove, substituting for the universe-ensouling power the universe itself, that is, the substance of it, or the deity, and attributing reason to it, inasmuch as on the one hand the rational (KoyiK6v) is better than the irrational, and on the other, that which is found in the parts must belong to the whole (Sext. Emp. adv. Math. ix. 104, 101 ; Cic. de Nat. Deor. ii. 8). In this universe-fashioning fire there must dwell not merely a concomitant consciousness, but a foreseeing one (Cic. de Nat. Deor. ii. 22), that is, the eternal deity extended throughout the whole universe, must produce (drjjj.iovp'ye'iv, Diog. Laert. vii. 134, 136) every thing. The doubt of Ariston, whether God could be a being possessed of life (Cic. de Nat. Deor. i. 14) seems to have been directed against Zenon's further definitions, which have not come down to us. Again, Zenon defined the deity as that law of nature which ever accom- plishes what is right, and prevents the opposite (Cic. I. c), as the energy which moves itself and operates according to the laws of impregnation (A6yoi cnnpiuaTLKoi, Diog. Laert. vii. 148; Cic. de Nat. Deor. ii. 39), and identified it, or Zeus, with spirit and predestination, or unconditioned necessity (Stob. Eel. Phys. i. 178; Diog, Laert. vii. 88, 148, &c., 156), without detriment to the foresight and free self-determination attributed to it (Cic. de Nat. Deor. ii. 22). He seems to have endeavoured to refer the diflFerent chief deities of the Greek mythology to the different fundamental modes of manifestation of the single divine primary power (Ibid. i. 14, comp. Diog. Laert. vii. 147, 149). He must have regarded individual souls as being what the world-soul was ; as of the nature of fire, or as warm breath (irv^vfia eudep/xov^ Cic. Tusc. i. 9, de Nat. Deor. iii. 14, comp. Plut de ph.pl. Decret. iv. 3; Diog. Laert. vii. 156), and therefore as perishable (Diog. Laert. /. c). The threefold division of the soul attributed to him (TertuUian. de Anima^ c. 14) is obscure, if not dubious. But however he may have divided it, he must have referred its different activities to one and the same fundamental power (riyrffioviKov, Sext. Emp. adv. Math. ix. 102 ; comp. Euseb. Praep. Ev. xv. 20). Zenon, coinciding with the Cynics, and with equal stringency, recognised in the most decided manner the unconditional nature of moral obligations, and that only that which answers to them is valuable in itself ; but departed from them partly in the deduction and definition of them, partly and chiefly^ in this, that by paving the way for the separation of the form and the purport or objects of our actions, he undertook, with reference to the domain of the (so-called) indifferent^ to demonstrate a rela- tive value in that which accords with natural impulses, and so to oppose the harsh contempt of the Cynics for custom, without however allowing that the gratification of mere natural wants, and the external good things which serve that end, have any value in themselves. In order to bring forward prominently the unconditional value of the moral (Stob. Eel. Eth. p, 154) he termed it, fol- lowing the example of the Eretrio-Megaric school, the single, sole and simple good (Cic. Acad. j. 16. 2) which, for that very reason, is that which alone should be striven after and praised for itself (Cic; 4 p 2
