 Robert Boyle’s variant belongs more to philosophy of science than theory of perception. It is integral to the corpuscular theory (hereafter “CT”), the mechanist natural philosophy he promotes. He is an avid experimentalist and prolific author of works on ethics, theology, natural religion, and both alchemical and mechanist natural philosophy (Stewart 1991: xi–xii, xv–xvi; Anstey 2000: 9). Boyle strongly opposes any intrusion of metaphysical and logical entities in natural philosophy (Boyle 1666 [1991: 3, 8, 22, 28]; Stewart 1991: xiii). The targets are Suarez’s real qualities and scholastic accidental and substantial forms. The former, as Boyle understands them, are entities that naturally inhere in material substance but have independent causal powers (see Boyle 1666 [1991: 21–2]). Boyle avoids controversial metaphysical doctrines that divide mechanists, such as Epicurean atomism, innate motion, Cartesian essences and the endless actual separation of parts of bodies (1666 [1991: 7–8]). According to CT, observable bodies are composed of very small relatively stable corpuscles, composed of minima naturales with tightly cohering parts rarely separated in nature (Anstey 2000: 10–11, 43–4).