The texts gathered for this issue revolve around a paradox: the fact that the imaginary, which exposes yet to the unreal, is a necessary ingredient of the action, which inscribes us in the most concrete reality. From Bachelard, and authors with whom his thought come into resonance, it is about to show that the imagination and the reverie, far from being remote from the reality and the imperatives of the “real life”, are essential for our action in the world.