Psyche and Locomotility

The 'ground' of Kant's Groundwork can be recognized as the traditional tri-partite concept of the Psyche--"Nature" as the Vegetative, "Will" as the Locomotive, and "Reason" as the Calculative part.  His primary aim is to demonstrate that the third can liberate the second from the influence of the first.  Now, one criticism of his effort, e. g. Schopenhauer's, is that Calculation is always at bottom in the service of Vegetative processes, as Hume claims.  Another is implicit in Freud's concept of the Psyche--that Calculation is actually determined by social forces.  However, regardless of their merits, neither of them addresses the internal problem that eventually emerges, with which Kant wrestles unsuccessfully.  For, as he discovers, the possibility of liberating the Will, via Reason, from organic need, presupposes the inherent independence of Locomotility from both of the other two divisions of the Psyche.  He, thus, shares with his critics, and with most other theorists of the Psyche, a neglect, if not a suppression, of that independence, without which a study of human motivation would be empty.