Schwinger’s action principle,supersymmetry and path integrals

We use Schwinger’s action principle in quantum mechanics to obtain the quantisation from Lagrangian for the fermionic variables, as well as when it contains auxiliary coordinates. We illustrate this with a supersymmetric Lagrangian which naturally includes auxiliary variables. We further show that the action principle also leads to Feynman’s path integral quantisation, which is aesthetically pleasing.