Rational Thought and Imagination - Pensée Rationnelle Et Imagination

Book excerpt: Etymologically, "rational" derives from the Latin "ratio", relating to calculation. The word calculation recalls an ancient practice of handling small pebbles. Rational thought is a thought that calculates. A computer rationally performs all the calculations one wants - logical calculations included. Should we think that it thinks? Descartes in Règles pour la Direction de l'Esprit does not think this way. On closer inspection, his Method is rather a way to organize findings of the imagination. Resulting from 3 dreams of Descartes - dreams as rational as all the others - the Method is however not foreign to the principles of the division of labor as deployed in the Dutch industry of the time. Given a goal, the Method will probably achieve it. But where do its goals come from? Genius - that of Descartes included - is an incomparable encounter. It wanders, but it finds, and suddenly revolutionizes entire semantic fields. Like Darwinian pre-adaptations at work in biological evolution, genius creates, in one single move, both the solution and its problem . Imagination does not come from Heavens, but is rooted in Evolution. The work of 3 Nobel Prize winners on the spatial imagination of mice (2014) and two other Nobel Prize winners on adaptive immunity (1972 and 1987) provide an idea of ​​some of the mechanisms implemented by living beings.