Meditations on First Philosophy is a philosophical treatise by René Descartes. Originally published in Latin in 1641, the text would go on to influence European and global philosophical traditions. In this work, Descartes argues for the existence of God and the immortality of the soul. Two of its major contributions to philosophy are mind/body dualism and the famous phrase “I think, therefore, I am.” The book comprises six meditations wherein Descartes seeks to doubt all his previously held beliefs in the hope of establishing clear and distinct knowledge. He attempts to strip reality of all unnecessary attributes so that its true essence can be known. Descartes attempts to provide arguments that will convince even atheists and skeptics that God exists and the soul is immortal.

Summary

Descartes begins the Meditations with a respectful letter to the Faculty of Theology in Paris defending the validity and authority of his work. This letter would have proved very important in Descartes’s time due to the climate of religious intolerance. Descartes then outlines the contents of each meditation, stating that he is aware of his susceptibility to error.

Descartes begins his first meditation by introducing his method of inquiry. He states that he will seek to doubt all things and examine whether he can find any indubitable truths. He doubts that he is sitting by a fire and that his hands are his own. The dream argument is then presented, as Descartes observes that one cannot always differentiate between wakefulness and sleep with ease. In the second meditation, Descartes begins to differentiate between the mind and the body. To do so, he experiments with wax. He finds that, once the wax has melted, it appears as a completely new object to the senses. The wax’s original qualities of color, weight, height, and smell have been replaced with different qualities. How then, Descartes asks, does one still know that this piece of the wax is the same object with which he began the experiment? This question leads Descartes to differentiate, broadly, between externality, which pertains to particulars and can undergo infinite change, and internality, which pertains to universals and constitutes continuity amid change. This distinction allows Descartes to state that physical bodies adhere to a certain, and malleable, presentation of particulars, whereas the soul is indivisible. Descartes also proclaims in this meditation that because he thinks, and cannot doubt that he is thinking, he can be certain that he exists.

In the third meditation, Descartes argues for the existence of God. He states that since he has a conception of a being greater than him, that being must exist because an effect cannot be greater than its cause. Since Descartes is a finite being, the only way he could have come to grasp an infinitely perfect being is if such a being placed the thought in him. In the fourth meditation, Descartes differentiates between truth and falsity. He posits human understanding as finite and thus susceptible to error. Yet, if God is perfect, must not the faculties instilled in us by Him be reliable? Descartes states that error arises due to human free will and the misuse of our intellectual faculties. Free will allows us to form opinions about things that our understanding does not fully grasp. In the fifth meditation, Descartes presents pure mathematics as the mode of substance that can be grasped by the soul.

In the final meditation, Descartes states that facts about material bodies, as well as mathematical truths, can be known. The body pertains to the senses and thus provides us with only adventitious knowledge. For example, if one feels heat, they know a source of heat is near. In this section, Descartes states that the body and mind are so inherently intertwined that it is only through a grueling meditation that they can be seen to possess different natures.