Aristotle in his work Poetics defined what he termed, “the three unities”. The neoclassical form of these unities are defined as unity of action, unity of place and unity of time. Basically they were constraints placed on any dramatic work.
- The unity of action: a play should have one main action that it follows, with no or few subplots.
- The unity of place: a play should cover a single physical space and should not attempt to compress geography, nor should the stage represent more than one place.
- The unity of time: the action in a play should take place over no more than 24 hours.
These are excellent principles for the design of an interactive system. But considering the Six Hats, Six Coats concept I want to add three more unities:
The unity of matter: a play should have only the props required by the actions.
The unity of goal: a play should have only one moral.
The unity of people: a play should have only the cast required to execute the actions.
So, there you have it. A modification of the neoclassical interpretation of Aristotle’s unities and another pillar in support of the Six Hats, Six Coats model.