Spinoza engaged with topics connected with natural philosophy throughout his philosophical career and his writings. His metaphysics, and his substance monism, entail that Extension (which, arguably, can be understood as geometrical space) defines the essential property of all bodies, and belongs to the only substance (God) as one of its attributes. In this context, for instance, Spinoza denies the possibility of a vacuum (like Descartes) and conceives of Extension, as an attribute, as infinite but as actually indivisible (cf. E1p15s; Ep12). This metaphysical commitment shapes Spinoza’s understanding of the physical world, which must be fully explained by appealing to the notions of matter (Extension) and motion (and rest) only. In this sense, Spinoza’s engagement with physics falls in the broad mechanist orientation that gains traction during the mid seventeenth century.