Rational Thought and Imagination - Pense Rationnelle et Imagination

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 Rgles 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.