Boyle Robert (1627–91), British chemist and physicist who was a major figure in seventeenthcentury natural philosophy. To his contemporaries he was ‘the restorer’ in England of the mechanical philosophy. His program was to replace the vacuous explanations characteristic of Peripateticism (the ‘quality of whiteness’ in snow explains why it dazzles the eyes) by explanations employing the ‘two grand and most catholic principles of bodies, matter and motion,’ matter being composed of corpuscles, with motion ‘the grand agent of all that happens in nature.’ Boyle wrote influentially on scientific methodology, emphasizing experimentation (a Baconian influence), experimental precision, and the importance of devising ‘good and excellent’ hypotheses. The dispute with Spinoza on the validation of explanatory hypotheses contrasted Boyle’s experimental way with Spinoza’s way of rational analysis. The 1670s dispute with Henry More on the ontological grounds of corporeal activity confronted More’s ‘Spirit of Nature’ with the ‘essential modifications’ (motion and the ‘seminal principle’ of activity) with which Boyle claimed God had directly endowed matter. As a champion of the corpuscularian philosophy, Boyle was an important link in the development before Locke of the distinction between primary and secondary qualities. A leading advocate of natural theology, he provided in his will for the establishment of the Boyle Lectures to defend Protestant Christianity against atheism and materialism. See also MECHANISTIC EXPLANATION , PHILOSOPHY OF SCIENCE , SPINOZ. A.G.