The stochastic variational principle which applies to diffusions and extremises the mean value of the classical action is generalised to include non-Markovian diffusions. A whole family of different stochastic actions, labelled by a time-dependent parameter, is obtained and all of them are shown to lead to the Schrodinger equation. As a result, the well known degeneracy of the class of stochastic processes which correspond to a single quantum state is recovered. It is also related to an arbitrariness in the choice of the noise which can occur in two places: in the definition of the noise, through the time-dependent parameter, and in the auto-correlations of the noise which, although constant during the variational method, remain undetermined. The whole scheme is given a covariant form.
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