Regarded as the founder of modern chemistry and a champion of empirical experimentation, Boyle was committed to the explainability of the universe on mechanical principles. Ussher was an early mentor. Boyle became central to the experimentalist circle around Wilkins (including Wren, Ward, Locke, Willis and Lower), the nucleus of the future Royal Society. Hooke (a friend) and later Papin were his assistants. Oldenburg was a natural ally (Boyle published through him), Hartlib a close friend. Leibniz met him on a London visit; Leeuwenhoek, Fatio, Bayle and Aubrey all corresponded. Locke and Newton spent long hours discussing mystical ideas with him.