The history of dual-process thinking

This paper reviews the history of the dual-mode information processing idea in philosophy, psychology, and cognitive science. It tracks how the concept that human thinking works through two separate but interconnected systems has developed from ancient times to now. The review looks at early philosophical ideas that suggested two processes in human thought. It points out Plato's separation of reason and appetite, and Aristotle's division of the soul into rational and irrational parts. Moving to modern times, the paper discusses how dual-process theories emerged in 20thcentury psychology. It covers William James's ideas of associative and true reasoning, and Freud's theories of conscious and unconscious mental processes. The review then focuses on formal dual- process theories in cognitive and moral psychology from the 1970s onwards. During this time frame, researchers began to systematically study and test these theories. By following this historical path, the paper aims to show how the idea of dual-mode information processing has grown and become important in our understanding of human thinking across different fields and time periods.