  We provide an epistemological analysis of the developments of relativistic
cosmology from 1917 to 2006, based on the seminal articles by Einstein, de
Sitter, Friedmann, Lemaitre, Hubble, Gamow and other main historical figures of
the field. It appears that most of the ingredients of the present-day standard
cosmological model, such as the accelation of the expansion due to a repulsive
dark energy, the interpretation of the cosmological constant as vacuum energy
or the possible non-trivial topology of space, had been anticipated by
Lemaitre, although his papers remain desperately unquoted.
