Page "Proclus" Paragraph 13

The first principle in Neoplatonism is the One ( Greek: to Hen ).

It is the principle which produces all Being.

For this reason, the Neoplatonists thought that the One could not itself be a being.

If it were a being, it would have a particular nature, and so could not be universally productive of all being.

Because it is beyond being ( epekeina tes ousias is a phrase from Plato's Republic 509b ), it is also beyond thought, because thinking requires the determinations which belong to being: the division between subject and object, and the distinction of one thing from another.

For this reason, even the name The One isn't a positive name, but rather the most non-multiple name we can think of, a name derived from our own inadequate conception of the simplicity of the first principle.

The One causes all things by conferring unity, in the form of individuality, on them, and in Neoplatonism existence, unity, and form tend to become equivalent.

The One causes things to exist by donating unity, and the particular manner in which a thing is one is its form ( a dog and a house are one in different manners, for example ).

As the One confers individuality it is in reality the principle of plurality.

Because the One makes things exist by giving them the unity which makes them what they are as distinct and separate beings, the Neoplatonists thought of it also as the source of the good of everything.

So the other name for the One is the Good.

The first principle isn't double, however.

Instead, all things have a double relation to it, as coming from it ( One ) and then being oriented back towards it to receive their perfection or completion ( Good ).