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

For if each series suffers something which is the same [or a certain sameness,] there is something in each which is the leader, and the cause of this sameness. For as all beings are from unity, so every series is from unity. But again, all imparticipable monads are referred to the one; because all of them are analogous to the one. So far therefore, as they also suffer something which is the same through an analogy to the one, so far a reduction of them to the one is effected. And so far indeed, as all of them are from the one, no one of these is a principle. But so far as each is imparticipable, so far each is a principle. Hence, being the principles of certain things, they are suspended from the principle of all things. For that is the principle of all things of which all things participate. All things however alone entirely participate of the first; but of other things not all, but certain things participate. Hence also that [i.e. the ineffable] is simply the first, but other things are firsts with reference to a certain thing, but simply are not firsts.