The reason why, since Descartes, nobody has found a solution to the mind–body problem seems to be that the problem itself is a false or pseudo-problem. The discussion has proceeded within a pre-Cartesian conceptual framework which itself is a source of the difficulty. Dualism and all its alternatives have preserved the same pre-Cartesian conceptual framework even while denying Descartes’ dualism. In order to avoid this pseudo-problem, I introduce a new perspective with three elements: the subject, the observed object, and the conditions of observation (given by the internal and external tools of observation). On this new perspective, because of the conditions of observation, the mind and the brain belong to epistemologically different worlds.