These arguments not valid against the Megarici.
Now these arguments of Aristotle are by no means valid against the Megarics, whose doctrine, though apparently paradoxical, will appear when explained to be no paradox at all, but perfectly true. When we say that the architect has power to build, we do not mean that he has power to do so under all supposable circumstances, but only under certain conditions: we wish to distinguish him from non-professional men, who under those same conditions have no power to build. The architect must be awake and sober: he must have the will or disposition to build:[54] he must be provided with tools and materials, and be secure against destroying enemies. These and other conditions being generally understood, it is unnecessary to enunciate them in common speech. But when we engage in dialectic analysis, the accurate discussion (ἀκριβολογία) indispensable to philosophy requires us to bring under distinct notice, that which the elliptical character of common speech implies without enunciating. Unless these favourable conditions be supposed, the architect is no more able to build than an ordinary non-professional man. Now the Megarics did not deny the distinctive character of the architect, as compared with the non-architect: but they defined more accurately in what it consisted, by restoring the omitted conditions. They went a step farther: they pointed out that whenever the architect finds himself in concert with these accompanying conditions (his own volition being one of the conditions) he goes to work — and the building is produced. As the house is not built, unless he wills to build, and has tools and materials, &c. — so conversely, whenever he has the will to build and has tools and materials, &c., the house is actually built. The effect is not produced, except when the full assemblage of antecedent conditions come together: but as soon as they do come together, the effect is assuredly produced. The accomplishments of the architect, though an essential item, are yet only one item among several, of the conditions necessary to building the house. He has no power to build, except when those other conditions are assumed along with him: in other words, he has no such power except when he actually does build.
[54] About this condition implied in the predicate δυνατός, see Plato, Hippias Minor, p. 366 D.
His arguments cited and criticised.
Aristotle urges against the Megarics various arguments, as follows:—1. Their doctrine implies that the architect is not an architect, and does not possess his professional skill,[55] except at the moment when he is actually building. — But the Megarics would have denied that their doctrine did imply this. The architect possesses his art at all times: but his art does not constitute a power of building except under certain accompanying conditions.
[55] Aristot. Metaph. Θ. 3, 1047, a. 3. ὅταν παύσηται (οἰκοδομῶν) οὐχ ἕξει τὴν τέχνην.
2. The Megaric doctrine is the same as that of Protagoras, implying that there exists no perceivable Object, and no Subject capable of perceiving, except at the moment when perception actually takes place.[56] On this we may observe, that the Megarics coincide with Protagoras thus far, that they bring into open daylight the relative and conditional, which the received phraseology tends to hide. But neither they nor he affirm what is here put upon them. When we speak of a perceivable Object, we mean that which may and will be perceived, if there be a proper Subject to perceive it: when we affirm a Subject capable of perception, we mean, one which will perceive, under those circumstances which we call the presence of an Object suitably placed. The Subject and Object are correlates: but it is convenient to have a language in which one of them alone is introduced unconditionally, while the conditional sign is applied to the correlate: though the matter affirmed involves a condition common to both.
[56] Aristot. Metaph. Θ. 3, 1047, a. 8-13.
3. According to the Megaric doctrine (Aristotle argues) every man when not actually seeing, is blind; every man when not actually speaking, is dumb. — Here the Megarics would have said that this is a misinterpretation of the terms dumb and blind; which denote a person who cannot speak or see, even though he wishes it. One who is now silent, though not dumb, may speak if he wills it: but his own volition is an essential condition.[57]
[57] The question between Aristotle and the Megarics has not passed out of debate with modern philosophers.