in each science are those ignorant questions which are of a certain quality geometrical? whether also is a syllogism, from ignorance, a syllogism composed from opposites or a paralogism, but according to geometry, or from another art, as a musical interrogation is ungeometrical, about geometry but to imagine that parallel lines meet is in a certain respect geometrical, and after another manner ungeometrical? For this is two-fold, in the same way as what is without rhythm; and the one is ungeometrical because it possesses not (what is geometrical), as what is without rhythm; but the other because it possesses it wrongly—and this ignorance which is from such principles, is contrary. In mathematics however there is not in like manner a paralogism, because the middle is always two-fold, for (one thing) is predicated of every individual of this, and this again of another every, but the predicate is not called universal; those, nevertheless, it is possible, we may see by common perception, but in argument they escape us. Is then every circle a figure? If any one should delineate it, it is clear. But what, are verses a circle? They are evidently not so.
