If there is perfect determinism then there is such a thing as the complete state of the universe in its moment to moment cross-sections, and it is this state that evolves according to a one to one rule going forward. The same rule also goes backwards, and if it is one to many in that direction, the many concerned is always very restricted. This would certainly be enough to do away with causality, or to reveal it as merely notional, a function belonging only to the sub-phenomenon of a certain kind of mind. Indeed the relation of mind to the presumed state of the universe is unspecified, and in so far as everything belonging to mind is smeared over time, both forward and backward without limit, there is nothing to preclude what can only be described as freedom of the will. This thought experiment amounts to nothing more than a mapping of Kant's noumenal freedom onto the (idea of the) deterministic completeness of the phenomenal. Its point is only to do away with the misleading question of freedom of the will.