Early Modern Philosophy: Descartes and the Rationalists

A pioneer of early modern philosophy, René Descartes set the goal of building a foundation for knowledge that is absolutely certain. Trace the chain of reasoning in his Meditations on First Philosophy that led him to the self-evident truth of his own thinking existence. Look at other conclusions reached by Descartes in this remarkably subtle work.

Why was Descartes so obsessed with certainty? Delve into The Discourse on the Method, which includes an intellectual autobiography. A key step was the time he spent alone in a stove-heated room, when he concluded that a single individual using reason can get closer to the truth than the aggregate of learning contained in all books. Follow the revolutionary deductions he reached with this method.

In his Discourse, Descartes outlines a provisional moral code, but the full development of his ethical system emerges through his correspondence with Princess Elisabeth of Bohemia. A gifted philosopher, she posed challenging questions that prompted him to rigorously refine his ideas. Their colloquy explored happiness, virtue, emotions, and the passions, with a strong emphasis on practical ethics.

Descartes's works prompted Lady Anne Conway, a reclusive English noblewoman and philosopher, to set down her ideas, which bridged metaphysics, ethics, and theology in sharp contrast to Descartes's system. Drawing on her posthumously published treatise, Dr. Reid summarizes her influential critique of Cartesian dualism and her vitalist conception of all reality, which incorporates reincarnation.

While Descartes argued that mind and body are two distinct substances, Baruch Spinoza, proposed that there is only one substance, which he identified as God or Nature. Everything else, including mind and body, are modes or expressions of this one substance. Spinoza's God is not a personal deity but an infinite, impersonal substance that encompasses all of reality.