  Even today, the concept of entropy is perceived by many as quite obscure. The
main difficulty is analyzed as being fundamentally due to the subjectivity and
anthropocentrism of the concept that prevent us to have a sufficient distance
to embrace it. However, it is pointed out that the lack of coherence of certain
presentations or certain preconceived ideas do not help. They are of three
kinds : 1) axiomatic thermodynamics; 2) inconsistent solutions of certain
paradoxes; 3) reluctance of physicists to the simplification provided by
information theory. The purpose of this paper is to examine these points in a
didactic way by paying attention to the structure of the theory, what are the
foundations, how ideas articulate, with a peculiar focus on their consistency
and economy. It is shown how entropy can be introduced in a more consistent and
economical manner with the help of information theory, which from the start
takes into account its subjective nature, finally allowing a more intuitive
understanding.
