  The notions of time in the theories of Newton and Einstein are reviewed so
that certain of their assumptions are clarified. These assumptions will be seen
as the causes of the incompatibility between the two different ways of
understanding time, and seen to be philosophical hypotheses, rather than purely
scientific ones. The conflict between quantum mechanics and (general)
relativity is shown to be a consequence of retaining the Newtonian conception
of time in the context of quantum mechanics. As a remedy for this conflict, an
alternative definition of time -- earlier presented in Kitada 1994a and 1994b
-- is reviewed with less mathematics and more emphasis on its philosophical
aspects. Based on this revised understanding of time it is shown that quantum
mechanics and general relativity are reconciled while preserving the current
mathematical formulations of both theories.
