Evidence is recalled of the strong opposition of Niels Bohr, at the time of
the Old Quantum Theory 1.913-25, to the Lichtquanten hypothesis of Einstein.
Some episodes with H.A. Kramers, J.C. Slater and W. Heisenberg are recollected;
Bohr's changing point of view is traced back to some philosophical antecedents
and to his endeavour to deduce quantum results from the Correspondence
Principle. Some consequences for the future interpretation of Quantum
Mechanics, specially to the Complementarity Principle, are considered.Comment: 15 page