6 ideas
Irvine argues insights surface from unconscious processing rather than deliberate reasoning, and the conscious mind receives them as finished gifts. Incubation lets the subconscious recombine material and present a conclusion whole.
He classifies aha experiences into religious, moral, scientific, mathematical, artistic and other types. Despite different content they share a common phenomenology of sudden certainty.
Insight rewards those who load a problem into the mind then relax rather than grind. Play, walking and distraction, not effortful concentration, tend to trigger breakthroughs.
A flash of insight is only a hypothesis and must be checked by conscious reasoning. Many epiphanies feel certain yet prove wrong on examination.
Creative people differ less in raw processing power than in openness to the fragmentary signals the subconscious sends. Attention to those signals is what distinguishes them.
Irvine holds that the disposition to have insights is trainable. Deliberately courting novelty, open questions and unfinished problems raises the rate of epiphany.