Abstract(s)
Though Karl Popper's short paper on the rationality principle may not be the most
frequently discussed of all of his writings on epistemological matters, it is very probably the
most radically criticized. The fact that this champion of falsifiability suggested in this text not
to reject a principle that he emphatically declares false has always been a source of
embarrassment for his disciples and has often been characterised by his adversaries as a rather
shameful theoretical development. In the present paper, I would like to show that, in spite of
this fact, Popper's views on rationality, while at moments somewhat awkwardly formulated, are
much more sensible than it is usually acknowledged and that they might even be considered as
one of his most interesting contributions, and surely as his most underestimated one.