Today's AI, particularly neural networks, stems from a long tradition in cognitive science where psychologists used mathematical models to understand human thought. Key advances in neural nets were made by researchers trying to replicate how human minds work, not just build intelligent machines.

Harris explains that patients with severed brain hemispheres reveal a fascinating truth: the language-dominant left hemisphere will confidently invent false reasons for actions performed by the right hemisphere. This "interpreter" module just makes up stories, suggesting our sense of rational self-control is partly an illusion.

Even Donald Hoffman, proponent of the consciousness-first model, admits his emotions and intuition resist his theory. He relies solely on the logical force of mathematics to advance, demonstrating that groundbreaking ideas often feel profoundly wrong before they can be proven.

Brain activity can predict a person's choice up to ten seconds before they are consciously aware of making it. This suggests that what we perceive as free will is often our brain rationalizing a decision already made subconsciously, challenging traditional models of deliberate action.

Thought is fundamentally non-linguistic. Evidence from babies, animals, and how we handle homophones shows that we conceptualize the world first, then translate those concepts into language for communication. Language evolved to express thought, not to be the medium of thought itself.

Daniel Kahneman and Amos Tversky developed their theories by studying their own cognitive biases. They created simple questions or "riddles" where they knew the logical answer but still felt an intuitive pull toward the wrong one. This self-reflective methodology allowed them to craft experiments that were compelling to non-psychologists like economists.

Amidst psychology's replication crisis, the Stroop effect stands out as an exceptionally robust and reliable finding. The cognitive interference felt when trying to name the ink color of a mismatched color word is so powerful and easy to demonstrate that it's seen as a bedrock truth of the field.

The famous 'Sally-Anne' task, used to test theory of mind in children, was not conceived by psychologists. Philosopher Daniel Dennett proposed the core idea in a commentary on a paper about chimpanzee cognition, highlighting how philosophy can generate testable hypotheses for empirical science.

A 2008 experiment showed researchers could predict a person's choice up to ten seconds before the person consciously made it. This suggests our conscious mind merely rationalizes decisions already made by unconscious processes, indicating free will is an illusion.