The Greek philosophers acknowledged several kinds of ψυχὴ, the nutritive, the sensitive, and the intellective.
But that the impassivity of the sensitive and intellective power is not similar, is evident in the sensoria and in sense.
The three heads signify the intellective, dianoetic, and doxatic powers.
But we never attain a similar intuition of God by the mere exercise of our intellective activity.
This is identical with the intelligence itself; it is what constitutes its intellective force and principle of activity.