The Six Books of Proclus on the Theology of Plato, Volume 2

Every thing which is partial in each order, is able to participate in a twofold respect of the monad which is in the proximately superior order, viz. either through its own wholeness or through that which is partial in the superior order, and co-ordinate with the thing according to an analogy to the whole series.

For if conversion is to all things through similitude, that which is partial in an inferior order, is dissimilar to that which is monadic and a whole in a superior order. And in short, is as that which is partial, to a whole, and as one order to another. But a partial nature is similar to a whole of the same series, through a communion of peculiarity, and to the proximately superior co-ordinate peculiarity through an analogous subsistence. It is evident, therefore, that through these media a conversion from one to the other is effected, as through similars to that which is similar.[255] For the one is similar as the partial to that which is partial, but the other as that which is the appropriate of the same series. But the whole of the superior series is dissimilar in both these respects.