During the Scientific Revolution, philosophers wondered how best to understand space. Many debates revolved around the account advanced in Descartes’s Principles of Philosophy (1644), and this chapter treats it as a focal point. Descartes argued for a return to the Aristotelian view that there is no difference in reality between space and matter, entailing that empty space—space empty of matter—is impossible. Over the next century, all kinds of philosophers attacked this position, and this chapter takes their rejections of Cartesian space as a starting point for exploring alternative views. A varied selection of philosophers who reject Cartesian space are discussed, in chronological order: Henry More, Samuel Clarke, Isaac Newton, Catharine Cockburn, and Gottfried Wilhelm Leibniz. The sheer breadth of alternative theories of space they advance demonstrates the metaphysical richness of this era. Nonetheless, there is a deep agreement among their alternatives: all the accounts agree on the features of space. This base agreement set the scene for Kant’s theory of space, advanced after the Scientific Revolution ended.