Early modern philosophy (also classical modern philosophy) is a period in the history of philosophy at the beginning or overlapping with the period known as modern philosophy. The early modern era of philosophy was a progressive movement of Western thought, exploring through theories and discourse, mind and matter, the supernatural, and civil life. It succeeded the Medieval era, sometimes referred to as the Dark Ages. Early Modern Philosophy is usually thought to have occurred between the 16th and 18th centuries, though some philosophers and historians may put this period slightly earlier. During this time, influential philosophers included Descartes, Locke, Hume, and Kant, all of whom contributed to the current understanding of philosophy.