  The broad debate on foundational issues in quantum mechanics, which took
place at the famous 1957 Chapel Hill conference on \textit{The Role of
Gravitation in Physics}, is here critically analyzed with an emphasis on
Richard Feynman's contributions. One of the most debated questions at Chapel
Hill was whether the gravitational field had to be quantized and its possible
role in wave function collapse. Feynman's arguments in favor of the
quantization of the gravitational field, based essentially on a series of
gedanken experiments, are here discussed. Then the related problem of the wave
function collapse, for which Feynman hints to decoherence as a possible
solution, is discussed. Finally, another topic is analyzed, concerning the role
of the observer in a closed Universe. In this respect, Feynman's many-worlds
characterization of Everett's approach at Chapel Hill is discussed, together
with later contributions of his, including a kind of Schr\"{o}dinger's cat
paradox, which are scattered throughout the 1962-63 Lectures on Gravitation.
Philosophical implications of Feynman's ideas in relation to foundational
issues are also discussed.
