Chapter 3.—Concerning the Arguments Which Nigidius the Mathematician Drew from the Potters Wheel, in the Question About the Birth of Twins.
It is to no purpose, therefore, that that famous fiction about the potters wheel is brought forward, which tells of the answer which Nigidius is said to have given when he was perplexed with this question, and on account of which he was called Figulus. 191 For, having whirled round the potters wheel with all his strength he marked it with ink, striking it twice with the utmost rapidity, so that the strokes seemed to fall on the very same part of it. Then, when the rotation had ceased, the marks which he had made were found upon the rim of the wheel at no small distance apart. Thus, said he, considering the great rapidity with which the celestial sphere revolves, even though twins were born with as short an interval between their births as there was between the strokes which I gave this wheel, that brief interval of time is equivalent to a very great distance in the celestial sphere. Hence, said he, come whatever dissimilitudes may be remarked in the habits and fortunes of twins. This argument is more fragile than the vessels which are fashioned by the rotation of that wheel. For if there is so much significance in the heavens which cannot be comprehended by observation of the constellations, that, in the case of twins, an inheritance may fall to the one and not to the other, why, in the case of others who are not twins, do they dare, having examined their constellations, to declare such things as pertain to that secret which no one can comprehend, and to attribute them to the precise moment of the birth of each individual? Now, if such predictions in connection with the natal hours of others who are not twins are to be vindicated on the ground that they are founded on the observation of more extended spaces in the heavens, whilst those very small moments of time which separated the births of twins, and correspond to minute portions of celestial space, are to be connected with trifling things about which the mathematicians are not wont to be consulted,—for who would consult them as to when he is to sit, when to walk abroad, when and on what he is to dine? —how can we be justified in so speaking, when we can point out such manifold diversity both in the habits, doings, and destinies of twins?
I.e. the potter.