The Rationalists is a collection of philosophical treatises by Rene Descartes, Benedict de Spinoza, and Gottfried Leibniz. You get Descartes’s Discourse on Method and Meditations, Spinoza’s Ethics, and Leibniz’s Monadology and Discourse on Metaphysics. By the middle of the 17th century, philosophy was finding its way out of the tired debates on religion and started to become a bit more scientific. The natural philosophers of the Renaissance started to place more importance on observable phenomena and experimentation rather than dictated dogma. The three philosophers collected here show how the school of rationalism started, matured, and culminated in an entirely different way of thinking.

Descartes’s writing tries to strip away all the nonessential from philosophy. If it isn’t absolute and eternal, then it isn’t true knowledge. Using reason alone, one can understand the universe. Even sense experiences aren’t absolute. His famous “cogito ergo sum” is a corollary showing that self-recognition isn’t something that is sensed, but rather reasoned, and being is absolutely true. Spinoza carries the rational baton a little further and tries to combine mathematical axioms and geometrical theorems into both philosophy and psychology. While Spinoza is often times dense and even purposefully obtuse, his propositions on emotions and human thinking are an interesting look at a proto-psychological science. Lastly, Leibniz’s works tries to both fundamentally break down human thought and the physical universe.

These three philosophers, separated from us by hundreds of years, give us an interesting look at humanity entering a new era of thought. They tried to desperately to understand their world and wanted to start from scratch. For those wondering, Descartes is most approachable of the three, and Spinoza’s work can be impenetrable at times, so you have to muscle through it. All in all, these works are intriguing and shed a little light on our philosophical heritage as modern thinkers. A deep and intellectual read. ( )