The Enigma of Reason: A New Theory of Human Understanding

In The Enigma of Reason, Mercier and Sperber solve the puzzle of human irrationality. By showing that reason evolved for communication and justification rather than solitary truth-seeking, they provide the evolutionary context for Brandolini’s law. It is a mandatory read for anyone who wants to understand why refuting bullshit feels like an uphill battle, and how our brains are wired to prioritise winning an argument over finding the truth.

Description

If reason is our greatest superpower, why are we so prone to conspiracy theories, stubbornness, and blatant illogic? Cognitive psychologists Hugo Mercier and Dan Sperber provide a provocative answer: we have been looking at reason all wrong. It didn’t evolve to help individuals find The Truth in isolation, it evolved as a social tool to help us justify our actions and convince others to join our side.

By tracing the evolution of intelligence from desert ants to Aristotle, the authors show that our supposed biases — like confirmation bias — are actually design features. Reason is an argumentative specialist. It is biased because its job is to find reasons that support our position, making us more effective social beings. It is a brilliant, elegant, and compelling rethink of what it means to be a rational animal.

Brandolini’s law is the natural byproduct of the evolutionary theory presented in this book. If the energy needed to refute bullshit is an order of magnitude bigger than the energy needed to produce it, it’s because our brains are reasoning engines designed for production, not refutation.

Mercier and Sperber show that we are incredibly lazy when producing reasons (generating bullshit is easy) but incredibly demanding when evaluating the reasons of others. This asymmetry is the engine of Brandolini’s law. We can churn out a justification in seconds, but because we are hardwired to defend our own territory, we force everyone else to do the heavy lifting of proof. This book explains the biological “why” behind the asymmetry: we aren’t bad at logic, we’re just evolutionary lawyers who prefer winning to being right.