 The appropriate evaluation of the knowledge argument remains controversial. The acceptability of its second premise P2 (Mary lacks factual knowledge before release) and of the inferences from P1 (Mary has complete physical knowledge before release) to C1 (Mary knows all the physical facts) and from P2 to C2 (Mary does not know some facts before release) depend on quite technical and controversial issues about (a) the appropriate theory of property concepts and their relation to the properties they express and (b) the appropriate theory of belief content. It is therefore safe to predict that the discussion about the knowledge argument will not come to an end in the near future.