The system of Plotinus is a system of necessary emanation, procession, or irradiation accompanied by necessary aspiration or reversion-to-source: all the forms and phases of Existence flow from the Divinity and all strive to return Thither and to remain There.
This Divinity is a graded Triad.
Its three Hypostases – or in modern religious terminology, ‘Persons’ – are, in the briefest description:
1 The One, or First Existent.
2 The Divine Mind, or First Thinker and Thought.
3 The All-Soul, or First and Only Principle of Life.
’Of all things the governance and the existence are in these Three.’