On the Dyad

From The Theology of Arithmetic by Iamblichus (4th century A.D.)

Among the virtues, they liken [the dyad] to courage: for it has already advanced into action. Hence too they call it ‘daring’ and ‘impulse.’

The dyad is all but contrasted to the nature of God in the sense that it is considered to be the cause of things changing and altering, while God is the cause of sameness and unchanging stability.