The concluding portion of this dialogue and of the work is taken up with the doctrine of the _Coincidence of Contraries_, which derives from that of the unity and coincidence of all differences, and which, although it was undoubtedly contained in his own system, Bruno obtained directly from Nicholas of Cusa. It is an indirect proof, from the side of particular things themselves, of the identity of all in the One. The first illustrations are geometrical.[285] The straight line and the circle, or the straight line and the curve, are opposites; but in their elements, or their _minima_, they coincide, for, as Cusanus saw, there is no difference between the smallest possible arc and the smallest possible chord. Again, in the _maximum_ there is no difference between the infinite circle and the straight line; the greater a circle is, the more nearly it approximates to straightness ... as a line which is greater in magnitude than another approximates more nearly to straightness, so the greatest of all ought to be superlatively, more than all, straight, so that in the end the infinite straight line is an infinite circle. Thus the maximum and the minimum come together in one existence, as has already been proved, and both in the maximum and in the minimum, contraries are one and indifferent. [Sidenote: "Verifications."] These geometrical illustrations are "signs" of the identity of contraries, those which follow are called by Bruno "verifications,"[286] the first of which is taken from the primary qualities of bodies. The element of heat, its "principle," must be indivisible--it cannot have differences within itself, and can be neither hot nor cold, therefore it is an identity of hot and cold. "One contrary is the 'principle' or starting-point of the other, and therefore transmutations are circular, because there is a substrate, principle, term, continuation and concurrence of both." So minimal warmth and minimal cold are the same. The movement towards cold takes its beginning from the limit of greatest heat (its "principle" in another sense). Thus not only do the two maxima sometimes concur in resistance, the two minima in concordance, but even the maximum and the minimum concur through the succession of transmutations. Doctors fear when one is in the best of health; it is in the height of happiness that the foreseeing are most timid. So also the "principle" of corruption and of generation is one and the same. The end of decay is the beginning of generation; corruption is nothing but a generation, generation a corruption. Love is hate, hate is love in the end; hatred of the unfitting is love of the fitting, the love of this the hatred of that. In substance and in root, therefore, love and hate, friendship and strife, are one and the same thing. Poison gives its own antidote, and the greatest poisons are the best medicines. There is but one potency of two contraries, because contraries are apprehended by one