 Hobbes’ conflict with Robert Boyle concerning the nature of natural philosophy in general, and the air-pump experiments in particular, took place over several years and in a series of  publications.[5]  Hobbes wrote Dialogus Physicus (1661; a second version appeared in  1668)[6]  as a dialogue aimed at criticizing Boyle’s New Experiments Physico-Mechanical (1660). Boyle responded to various criticisms in works such as An Examen of Mr. T. Hobbes his Dialogus Physicus de Natura Aëris (1662), An Examen of Mr. Hobbes’ Doctrine about Cold (1665), and Animadversions upon Mr. Hobbes’ Problemata de Vacuo (1674). The most comprehensive and influential treatment of this period of Hobbes’ life is Shapin and Schaffer’s Leviathan and the Air-Pump  (1985).[7]  This section will focus upon Hobbes’ criticisms of the air-pump experiments in the Dialogus Physicus with an aim of showing how they illuminate our understanding of Hobbes’ natural philosophy.