The Indefinite Dyad and The One

Some neo-Platonists refer to Plato's concept of The Unlimited as his 'Second Principle'.  But, his concept of The Limited is for them not his 'First Principle'.  For, in their systems, the First Principle is The One, and the Second is The Indefinite Dyad, with The Limited, i. e. The Definite Dyad a synthesis of the two.  In other words, for them, it is by virtue of The One that an indeterminate manifold becomes determinate, i. e. becomes quantifiable.  However, an alternative arrangement is suggested by the doctrine of Spinoza, who is interpreted by some to be influenced by Plotinus, one of the leading neo-Platonists.  For, in Spinoza's doctrine, his version of The One--Substance, or God, or Nature--is constituted by two parallel Attributes, one of which extends, the other of which connects.  In other words, in his doctrine, The Unlimiting and The Limiting are not subsequent to The One, but are, in fact, two complementary constituents of The One.  Thus, according to Spinoza, in terms of neo-Platonism, The One is nothing other than a combination of The Indefinite Dyad and The Definite Dyad, and in terms of the Philebus, it is nothing other than a combination of The Unlimited and The Limited.  And, in terms of Aristotle, it is nothing other than a combination of Material Causality, as has been defined here, and Formal Causality.  Implicit in all these cases is a rejection of the Parmenidean supremacy of the simple The One.