Experimental Reason and Groundwork

Before the foundation of a building is laid, the ground upon which it is laid needs to be suitably tested and prepared.  In other words, groundwork precedes founding.  Thus, any presumed equivalence between 'The Groundwork of the Metaphysics of Morals' and 'The Foundations of the Metaphysics of Morals' is profoundly misleading.  Similarly, given the synonymy of 'reason' and 'ground', Experimental Reason can be understood as the groundwork phase of Reason.  Thus, for example, the Cartesian Doubt that precedes the establishment of his Epistemological foundation, is Experimental Reason doing its groundwork.