Physica in John Locke's Adversaria and Classifications of the Branches of Knowledge
The framework of the various schemes of Physica in Locke’s classifications of knowledge (ca. 1670-1687) shows relevant traces of what may be defined, in a very broad sense, as an Aristotelian model: the internal divisions of this science are shaped into the classical ordering of the Stagirite’s physical works, as was common in seventeenth-century Aristotelian texts on natural philosophy. However, Locke’s schemes are also evidence of his uneasiness with that model, especially with reference to the first part—the one containing the fundamentals of physics, or physica generalis—and the last, concerning the objects of sense— one of the branches of physica specialis. This uneasiness was clearly due to Locke’s adherence to mechanism (in particular to Boyle’s mechanism) as well as to his empiricism. The last scheme of Physica (ca. 1687) shows Locke’s detachment from the Aristotelian model and his adhesion to Pansophism: the object of physica generalis, which in the earlier schemes was circumscribed to the material world, is re-conceptualised in broader terms which include spiritual beings. This later scheme is also evidence of a redefinition of Physica as a theoretical science, a point which was somewhat obscured in Locke’s previous schemes by the location of the discipline after the practical sciences. The various adversaria Locke wrote in 1677 help to illuminate his way of conceiving the object and scope of Physica; they show the relevance he attributed to the Baconian method of natural history, as well as the priority he assigned to useful knowledge with respect to speculative knowledge.