Plotinos: Complete Works, v. 3 In Chronological Order,...

What distinctions are admitted by continuous quantity? There is the line, the surface, and the solid; for extension may exist in one, two or three dimensions (and thus count the numerical elements of continuous size) instead of establishing species.389 In numbers thus considered as anterior or posterior to each other, there is nothing in common, which would constitute a genus. Likewise in the first, second and third increases (of a line, surface, and solid) there is nothing in common; but as far as quantity is found, there is also equality (and inequality), although there be no extension which is quantitative more than any other.390 However, one may have dimensions greater than another. It is therefore only in so far as they are all numbers, that numbers can have anything in common. Perhaps, indeed, it is not the monad that begets the pair, nor the pair that begets the triad, but it may be the same principle which begets all the numbers. If numbers be not derivative, but exist by themselves, we may, at least within our own thought, consider them as begotten (or, derivative). We conceive of the smaller number as the anterior, the greater as posterior. But numbers, as such, may all be reduced to unity.