What made this unusual is that Kahneman is a psychologist. Human irrationality is Kahneman’s great theme. There are essentially three phases to his career. It is an astonishingly rich book: lucid, profound, full of intellectual surprises and self-help value. It is consistently entertaining and frequently touching, especially when Kahneman is recounting his collaboration with Tversky. Now, this worries me a bit.
A leitmotif of this book is overconfidence. All of us, and especially experts, are prone to an exaggerated sense of how well we understand the world — so Kahneman reminds us. Surely, he himself is alert to the perils of overconfidence. Such sweeping conclusions, even if they are not endorsed by the author, make me frown. System 2, in Kahneman’s scheme, is our slow, deliberate, analytical and consciously effortful mode of reasoning about the world. System 1, by contrast, is our fast, automatic, intuitive and largely unconscious mode. More generally, System 1 uses association and metaphor to produce a quick and dirty draft of reality, which System 2 draws on to arrive at explicit beliefs and reasoned choices.