[Footnote 51: Cicero, in his Academ. Prior, ii. 92-94, has very just remarks on the obscurities and difficulties in the reasoning process, which the Megarics and others brought to view--and were blamed for so doing, as unfair and captious reasoners--as if they had themselves created the difficulties--"(Dialectica) primo progressu festivé tradit elementa loquendi et ambiguorum intelligentiam concludendique rationem; tum paucis additis venit ad soritas, lubricum sané et periculosum locum, quod tu modo dicebas esse vitiosum interrogandi genus. Quid ergo? _istius vitii num nostra culpa est_? Rerum natura nullam nobis dedit cognitionem finium, ut ullâ in re statuere possimus quatenus. Nec hoc in acervo tritici solum, unde nomen est, sed nullâ omnino in re minutatim interroganti--dives, pauper--clarus, obscurus, sit--multa, pauca, magna, parva, longa, brevia, lata, angusta, quanto aut addito aut dempto certum respondeamus, non habemus. At vitiosi sunt soritæ. Frangite igitur eos, si potestis, ne molesti sint. . . Sic me (inquit) sustineo, neque diutius captiosé interroganti respondes. Si habes quod liqueat neque respondes, superbis: si non habes, ne tu quidem percipis." The principle of the Sorites ([Greek: ê( sôritikê\ a)pori/a]--Sextus adv. Gramm. s. 68), though differently applied, is involved in the argument of Zeno the Eleate, addressed to Protagoras--see Simplikius ad Aristot. Physic. 250, p. 423, b. 42. Sch. Brand. Compare chap. ii. of this volume.] [Side-note: Controversy of the Megarics with Aristotle about Power. Arguments of Aristotle.] Of the positive doctrines of the Megarics we know little: but there is one upon which Aristotle enters into controversy with them, and upon which (as far as can be made out) I think they were in the right. In the question about Power, they held that the power to do a thing did not exist, except when the thing was actually done: that an architect, for example, had no power to build a house, except when he actually did build one. Aristotle controverts this opinion at some length; contending that there exists a sort of power or cause which is in itself irregular and indeterminate, sometimes turning to the affirmative, sometimes to the negative, to do or not to do;[52] that the architect _has_ the _power to build_ constantly, though he exerts it only on occasion: and that many absurdities would follow if we did not admit, That a given power or energy--and the exercise of that power--are things distinct and separable.[53] [Footnote 52: Aristot. De Interpret. p. 19, a. 6-20. [Greek: o(/lôs e)/stin e)n toi=s mê\ a)ei\ e)nergou=si to\ dunato\n ei)=nai kai\ mê\ o(moi/ôs; e)n oi(=s a)mphô e)nde/chetai, kai\ to\ ei)=nai kai\ to\ mê\ ei)=nai, ô(/ste kai\ to\ gene/sthai kai\ to\ mê\ gene/sthai.]]