  Through a very careful analysis of Dirac's 1932 paper on the Lagrangian in
Quantum Mechanics as well as the second and third editions of his classic book
{\it The Principles of Quantum Mechanics}, I show that Dirac's contributions to
the birth of the path-integral approach to quantum mechanics is not restricted
to just his seminal demonstration of how Lagrangians appear naturally in
quantum mechanics, but that Dirac should be credited for creating a
path-integral which I call {\it Dirac path-integral} which is far more general
than Feynman's while possessing all its desirable features. On top of it, the
Dirac path-integral is fully compatible with the inevitable quantisation
ambiguities, while the Feynman path-integral can never have that full
consistency. In particular, I show that the claim by Feynman that for
infinitesimal time intervals, what Dirac thought were analogues were actually
proportional can not be correct always. I have also shown the conection between
Dirac path-integrals and the Schr\"odinger equation. In particular, it is shown
that each choice of Dirac path-integral yields a {\it quantum Hamiltonian} that
is generically different from what the Feynman path-integral gives, and that
all of them have the same {\it classical analogue}. Dirac's method of
demonstrating the least action principle for classical mechanics generalizes in
a most straightforward way to all the generalized path-integrals.
