In Philosophy there are five branches of study, namely logic, value theory/ethics, metaphysics, epistemology, and politics. Epistemology, the study of the conditions under which something is known, is the branch that houses René Descartes’ Meditations. The Meditations were a series of essays written by Descartes in which he tried to solve the Problem of the Infinite Regress, which has plagued the epistemology branch of philosophy since the days of Socrates. The Problem of the Infinite Regress hinges on the idea that to know a thing, one must also know the parts of that thing. Either, one must then know the parts of the parts that make up that thing and so on till it stops at some arbitrarily defined point, which means only physicists know anything, or the regress never stops, which means no one can ever know anything ever. Occasionally relying on well-known philosophical principles and accepted truths from his time, Descartes leaves the Meditations as an account of his solution to the Problem of the Regress.
Descartes’ Meditations begin with him systematically rejecting the existence of everything; he rejects chairs, mountains, his body, and even others’ minds. Finally, he is left with the only thing he cannot reject, his own mind. Under these circumstances, Descartes comes up with the sentence, “Cogito ergo sum,” which roughly translates as “I think; therefore, I am.” Colloquially known as the Cogitio, it is a self-affirming sentence, the sentence proves itself true in either case.
Descartes then reaches for another idea floating around in philosophy at the time, the Principle of Sufficient Reason, which simply states, “The cause of something must be at least as real as its effect.”
Descartes then floats the concept that some ideas can be more real than people and that the Cogito was one such idea. According to Descartes, the Cogito was such a perfect thought that there was no way that a human could have thought of it. Instead, by the Principle of Sufficient Reason, the only thing “real” enough to cause the Cogito was God.
With this logic, God’s existence was basically proven to all philosophers of the 16th Century. God could therefore be considered the “First Cause,” the cause that leads to the existence of everything in our universe. And along with being responsible for creating the universe, God, in all his perfection, created the senses by which humans perceive His world. Descartes goes a bit further and states that because God is perfect, he would never create senses that were not perfect, thus all perception can be trusted as real. God also gives humans a Natural Light of Reason, or an innate truth detector for determining what exists and what does not. The Natural Light of Reason is innate because if the truth detector had to be acquired there would be another regress in knowledge caused by people with “malfunctioning” or bad truth detectors.
Suddenly things, whose existence could easily be doubted beforehand, could concretely exist...