Fashion, apparently irrational and whimsical, presents on the contrary a non-random way of managing the limits of rationality in the relations between individuals. Fashion is an inherently paradoxical phenomenon, as was observed at the beginning of its diffusion in the 17th century, a time that discovered, like the recent theory of organization, the necessity and the strategic role of disorder. Fashion relies on the stability of transition (everything changes, and this is the only thing we can rely on) and on the conformity with deviance (everyone wants to be original, and in this desire is like everyone else). Fashion works combining these paradoxes and neutralizing them in the form of banality. What can the theory of organization learn from the trivial mystery of fashion, that prevails on everyone just because nobody takes it seriously?