Another bit from the Alice book's "Design Methods" chapter:
Logic – Our society is biased towards the Western-rational-thought traditionally taught in schools – scientific method, for instance – so this design guide stresses the less understood areas of intuition and its “artsy” ilk. 4.8 But logic is useful. Analytical thought is a very good tool - just remember it is a tool not the only tool, nor always the best tool for a particular job. 4.9
In visual design, logic means something a bit different than in, say, trigonometry. Design logic can mean functional suitability (does it work? Or, this being theater, does it play?). Or it can mean the suitability of parts to the whole. If the set is all angles and prisms, that curved sofa contrasts. At another level, do angles – sharp, jagged, inhospitable – serve the theme of the play? Or do curves – soft, smooth, enfolding? Designs have internal logic. It’s important to make clear what rules apply. For instance, if you establish that stripes of blue tape on the stage mean “ocean” and for all of Act I the actors “splash” in it or skirt the edge of the “waves,” then in Act II you can’t logically tromp all over it like a blue floor!
4.8 In The Salmon of Doubt Douglas Adams explains: “Logic comes afterwards. It’s how we retrace our steps. It’s being wise after the event. Before the event you have to be very silly.”
4.9 At the beach this summer, read Zen and the Art of Motorcycle Maintenance for a fascinating discussion: the author calls these two thought traditions classical and romantic. For a refresher in logical process, read Ken Watanabe’s Problem Solving 101.
(The Lord of the Rings and Terry Pratchett gave me a taste for footnotes.)