[Sidenote: F] XXXV. ‘So much for that! May it reassure any one who is surprised at our dividing the natural processes of becoming and mutation into so many classes! Now comes another point, which I will ask you all to consider with me. Of the ultimate first principles, by which I mean unity and the undelimited two, the latter, as the element of all shapelessness and disorder, has been called Infinity; but unity by its nature limits and arrests what is void and irrational and undetermined in [Sidenote: 429] Infinity, and imparts shape, and fits it to receive and endure that definition of things apprehended by the senses which is implied in counting. These principles appear first in connexion with number; but I would rather say, universally, that plurality is not number until unity supervenes, as form upon matter, and cuts off from undetermined Infinity, more on this side, less on that. For plurality in each case only becomes number when it is determined by unity. Again, if unity be struck off, the undetermined two throws all into a confusion without balance or limit or measure. Now since form is not a withdrawal [Sidenote: B] of underlying matter but is shape and order thereof, both principles must necessarily be found in number, and hence arises the first and greatest difference or dissimilarity. The undetermined principle is the constructive cause of the even, the better one of the odd. Two is the first of the even numbers, three of the odd; out of them comes five, in its composition common to both lists, in its effect, odd. For when the sensible and corporeal was to be divided into several parts, in virtue of the inherent cogency of the Other, their number must not be the first even nor yet the first odd, but the third, that formed out of these, so that it may take its origin from both [Sidenote: C] principles, that which constructs the even and that which constructs the odd; for neither could possibly be separated from the other; each possesses the nature and power of a principle. Both principles then being paired, the better one checked the indeterminate when it was dividing up the corporeal; and prevailed; when matter was being distributed between the two it set unity in the middle, and did not allow an equal division of the whole. So a plurality of worlds has been brought into being by the “Other” quality in the undetermined, and by difference; but that plurality is odd, made so by the operation of “the Same” and “the Determinate”, and odd in such a sense that Nature was not allowed to advance beyond what was best. For if the unity had been without admixture [Sidenote: D] and pure, matter would have been exempt from any breaking up whatever; but as it has been mingled with the discriminative power of the two, separation and division were so far accepted; but there it stopped, the even overcome by the odd.