In the years after Martin Luther posted his ninety-five theses on the wall, the Medieval world explodes and thus dawns the Modern Period. Rene Descartes is born in 1596, in France, a country still feeling the aftershocks of that explosion sixty years later. In light of this knowledge, Descartes grows up in a world that feels uncertain and he sets out to rethink the foundations of knowledge. Subsequently, his work New Foundations for Knowledge focuses just on that concept, rethinking how knowledge is thought of. He sets out to answer this question, “How should we as a society reestablish philosophy, science, and inquiry in light of the upheaval and transition of the sixteenth century?” Throughout all his work, Descartes continuously answers this by one simple beginning, to start with doubt.
Rene Descartes’s name is synonymous with the ideology of doubt. Throughout his argument of Confessions, Descarte discusses how one must doubt everything. His basis for this is the fact that he once held beliefs as a child, beliefs that are now proven false. Therefore, following this pattern all adult beliefs should be doubted based on the fact that they are not concrete as they are based on perception senses. Furthermore, anything that allows for even a hint of doubt can’t serve as a basis for academic inquiry. If one can doubt something, then that fact should be thrown out entirely, due to the fact that it can never be fully one hundred percent believed. In addition, Descartes poses that people who are mentally ill do not know they are mentally ill. Those with schizophrenia for example can create people and a narrative that is completely different from reality. This is why the very basis of everything should be doubted, even if one is no longer a child, one could still be crazy and unaware of that fact, and one’s surrounding reality.
Descarte prefaces this doubt even further, believing that one should doubt one's senses as everyone can experience things in a different way. In fact, Descartes doubts his own surroundings, applying the concept of being in a dream as a grander scale metaphor. When one is dreaming, one fully believes in the reality that one is in, one can see, and feel, and hear. In short, he writes that it is possible that his mind is so powerful that he is imagining everything around him, just like what occurs in a dream. Due to the fact everyone can perceive things differently, there is reason to doubt every object's existence. Descarte then argues that one can not base knowledge on sensory perception because it is possible one's current reality could be a dream, a perceptive mistake, or even a hallucination.
However, in the midst of all of this, there are a few things that Descartes believes cannot be doubted. Descartes believes in the idea that there is such a thing as concrete knowledge which never changes. For example, two plus two will always equal four. Regardless of what your perception of two will always equal the value of two. This is a much more solid, more foundational basis of knowledge than one's own perception senses. What Descartes writes can be boiled down to a statement that is, “A square is always a square, I might not always be sane.” However, even though math is more stable than sensory knowledge, Descarte still finds a way to doubt math. He argues that since God is omnipotent,in the full sense of the word, there is a chance that His 2 + 2 is not 4, but is based on some other cosmic law or representation. Furthermore, it is also possible that there could be an evil deceiver or being tricking one’s mind into seeing things that aren’t there. This can be the same for any academic law or science, it is always a chance of human error or the chance that one is being deceived.