The doubt of Descartes
Even if one is largely ignorant when it comes to philosophy, they have no doubt heard the famous conclusion of the French philosopher and mathematician Rene Descartes: cogito ergo sum—that is, I think therefore I am. The rationality behind such a statement seems self-evident and beyond denial: if I am aware of my own thinking, then there must be an I (known as the ego) doing such thinking who, therefore, exists; in contrast, in order to deny such a statement there must be an I who is denying it and, therefore, thinking, and subsequently existing.
However, most people are unaware of what drove Descartes to arrive at such a bare and seemingly tautological conclusion.
Descartes began to embark on an epistemological—one’s epistemology is their theory of how knowledge is acquired--journey. He ideally wanted to build a theory of knowledge from the bottom up, and to do so would require the foundations of said theory to be so strong as to be unmovable and unquestionable; for if the foundations of one’s theory are shown to be invalid then the theory itself comes tumbling down into destruction. So, Descartes felt that he should begin by doubting everything he felt could be possibly doubted—e.g. the reality of the external world, the reliability of sense perception etc. The reasons behind such doubts were fueled by the possibility of an evil deity or demon: if it is even possible that there is an evil demon deceiving me in all the objects brought to my consciousness, then all objects are open to doubt. Thus, the endeavor that Descartes embarked on seemed geared towards disaster: what can constitute foundations of knowledge if everything can be doubted?
But there was one last epistemological hold out for Descartes: his own existence. The one aspect Descartes felt that the demon could not reach him was with regards to his own being. Might the external world be an illusion? Maybe. Might my senses be deceiving me continually? Possibly. But, might I ever be deceived that I do in fact exist? Not at all, thought Descartes. Thence emerges the famous cogito ergo sum, and from there began the foundation of Descartes epistemology.
But, was Descartes correct? Can everything be doubted, only to be left with the small shelter of belief in one’s own existence? Or, are there not other statements and beliefs that can be upheld with the certainty Descartes upheld his own existence with?
Descartes’ double standard
It turns out that, by Descartes own standards, his cogito ergo sum is not as resilient to doubt as he believed. For, cognition is simply the act of objects being presented, voluntarily or involuntarily, to the conscious subject; this is true with regards to introspection as well. My perceiving the computer sitting on my lap is simply the act of the sense datum of the computer being presented to my consciousness. My remembering the vacation I took last year is simply the act of the memorial imprints of said vacation being presented to my conscious awareness. These are the types of objects that Descartes claimed might not represent what we take them to represent.
But, what exactly is different with regards to being conscious of our own being? To engage in consciousness of my own being is simply for my consciousness to be presented with particular objects—i.e. my own thoughts, feelings, emotions. To participate in introspection is to bring the self, or ego, to the forefront of my consciousness. But, how do we know that this object (the ego) present to our consciousness is indeed a reality? Well, by Descartes’ standards, we don’t! The late Scholastic philosopher Peter Coffey articulates:
[W]e cannot assert the “self,” of which we become aware in all conscious activity to be real, or to exist really, without asserting the reality of the object revealed through this awareness; for we become aware of the thinking subject or self, not as a subject, but as an object[.]
But though Descartes was wrong regarding his epistemological convictions—or wrong about what grounds these convictions--we can still use his reasoning behind the cogito to build a bigger foundation for a theory of knowledge.
I think therefore I am, and more!
To reiterate, by affirming the cogito ergo sum, Descartes was making a specific judgment: he believed that the very fact of the “I the thinking subject” being an object of his consciousness implied that such an object had its being in reality. But, if Descartes could assert the objective existence of one such object present to his awareness, then why could he not assert the existence of other objects also present to his awareness in the same vein? The former can be doubted just as cogently as the latter. But if Descartes did indeed doubt the former (the reality of his own existence) then his epistemology would be self-defeating—i.e. “I am led to the conclusion that I doubt my own existence, yet such a statement ‘I do not exist’ can only be uttered by one who exists.” So, it seems that we must affirm that the object of the ego presented to the awareness of the subject exists; and, therefore, we now have reason to uphold the fact that objects present to a subject’s consciousness have an objective being in reality; for, if we can make such a judgment about one object, then there is nothing stopping us from making similar judgments about other objects, since the presentation of said objects is the same. May we misinterpret such objects? Sure. Might we occasionally make mistakes regarding the nature of said objects? Yes. But, we have no reason whatsoever, and all the reason to the contrary, to doubt that objects presented to a subject’s awareness have an objective existence in reality.
So, not only can we safely conclude that “I think, therefore I am”, but the reasoning behind such an inference also leads us to conclude judgments like “I have a computer on my lap” and “I went to Atlanta last November.” Ironically, Descartes implicit inferences lead us to affirm most of what he denied.