 Despite Descartes’ grounding of all scientific knowledge in metaphysical knowledge of God, his system contributes significantly to the advance of natural science in the period. He attacks the long-standing assumptions of the scholastic-aristotelians whose intellectual dominance stood in the way of the development of the new science; he developed a conception of matter that enabled mechanical explanation of physical phenomena; and he developed some of the fundamental mathematical resources – in particular, a way to employ algebraic equations to solve geometrical problems – that enabled the physical domain to be explained with precise, simple mathematical formulae. Furthermore, his grounding of physics, and all knowledge, in a relatively simple and elegant rationalist metaphysics provides a model of a rigorous and complete secular system of knowledge. Though major Enlightenment thinkers (for example Voltaire in his Letters on the English Nation, 1734) embrace Newton’s physical system in preference to Descartes’, Newton’s system itself depends on Descartes’ earlier work, a dependence to which Newton himself attests.