The constitutive principles approach to scientific theories is a neo-Kantian response to Quinean holism and philosophical naturalism. The approach attempts to be informed by, and inform, the best historical research in the history and philosophy of science. Proponents of the approach argue that there are some propositions (constitutive principles) in a scientific theory that in some way make possible (or, constitute) other propositions in the theory. Different versions of the approach will vary in how they flesh out the precise way in which constitutive principles 'make possible' other propositions. References to "constitution" in this literature are derived from the work of Kant. In Kant (1786), Kant attempts to give a firm metaphysical foundation to the science of Newtonian physics. Science, according to Kant, must be "ordered according to principles", and proper science (the paradigm of which is Newton's physics) must be ordered according to rational principles, that is, principles which hold by necessity and are known a priori.1 Kant demands that proper natural science be known with apodictic certainty, and this certainty can only be achieved on the basis of a science's "pure part", which grounds our a priori cognition of natural things.2 The concepts of proper science must be given constructions (in the vein of geometrical constructions) in intuition such that (1) these concepts are amenable to mathematization, and (2) these concepts are applicable to experience in a way such that laws may be generated through their deployment. The process by which Kant accomplishes (1) and (2) uses the resources of the analysis of cognition developed in Kant (1781). In particular, Kant's table of categories, which gives the concepts of pure understanding, must be adhered to in giving a complete construction of a new scientific concept, such as matter. In short, Kant identifies mental structures in his faculty psychology that order our experience of physical objects in a way that we can know for certain. These mental structures, according to Kant "constitute the object of knowledge" and make it possible for us to develop and test scientific theories. It is this notion of constitution, rather than the one found in contemporary metaphysics, that those who take the constitutive principles approach to scientific theories find inspiration in.
