The Art of Thinking Clearly

Rolf Dobelli collects short discussions of common reasoning errors. On his book page, he describes his role as interpreting and synthesizing research. The short format can give you a starting vocabulary, but attaching a bias name to a decision is not the same as explaining what should happen next.

Separate past spending from the next choice

Here is an original example. You bought a nonrefundable ticket for a workshop. On the morning of the event, the topic no longer matches what you need, and attending would take four hours. “I paid for it, so I have to go” treats the past payment as if attendance could recover it.

Compare the options from now onward. Attending may still offer useful material, social contact, or enjoyment. Staying home may allow a more relevant activity. Include remaining travel costs and any commitments to other people. The earlier payment is the same in both options; it does not by itself decide between them.

Do not overcorrect

Calling something a sunk cost is not a reason to abandon it automatically. If attending is still the best available use of the morning, going is reasonable. Similarly, a partly completed project may have valuable future benefits even if the original decision to start it was poor.

Write a two-column comparison headed “What changes if I continue?” and “What changes if I stop?” If a cost appears identically in both columns, it is unlikely to distinguish the choices. If stopping would incur a new cancellation fee, that fee does matter.

Read beyond the label

Use a chapter as a prompt to inspect assumptions, not as a diagnosis of another person's motives. Also consult the author's published corrections when checking an example or attribution. A compact popular account cannot show every qualification in the underlying research.

Choose this book for short entry points into reasoning topics. For a more extended treatment of probabilistic decisions and hindsight, see Thinking in Bets.