Doubt is central to the Meditations, as tearing down the mental foundations Descartes had built upon for the decades of his lifespan was the inspiration for the writing. The way Descartes describes this self-perceived doubt of the self and mind is as the Method of Doubt, which is split into three separate parts. The three parts are intricately connected by virtue of the way in which they spill into one another as if a metaphysical domino effect.
The first part is the Sensory Illusions Doubt, the idea that the world we perceive is not immune from fallacy. In a sense, our perception is open to illusions, or things that impact and sway the way we see things. This part is partially solved by the concept that even though we may see the world in its true form, it does not inherently mean there is not a world itself.
From this Descartes presents the Dreaming Doubt, or the idea that the waking world cannot be separated from our own dreams. In his view, it is virtually impossible to ascertain whether our surroundings are even real life or just a dream.
Descartes goes about stating that despite our surroundings, whether we are out in the world or deep within our own mindscape, we can find comfort in that the rules and mathematical principles that govern the universe apply to any reality. Even if one cannot trust their senses or surroundings, one can always escape from full doubt with the idea one’s knowledge and intellect are untouched.
From this, Descartes presents an idea that even turns one’s own trust in mathematics on its head: the Deceptive God Doubt. This concept presents the idea that everything we have ever known or will know is open to fallacy, as creation itself is flawed by virtue of a great progenitor who implanted flaw and error millennia ago.
The idea of an imperfect God implies the universe itself is unbalanced, and even the mathematical foundations upon which knowledge Is based are potentially incorrect, and thus cannot be trusted. The only way for Descartes to asway this overwhelming doubt is to ascertain the undeniable truths of our universe.
In the second meditation, he determines that our very existence is undeniable. From this basis of the existence of the self, one can ascertain that the self can think, and in turn, have a mind. In Descartes’s argument, he says that to question one’s existence or ability to think is intrinsically a self-defeating act, as to question this is to think, and to think is to exist. In his view, by all accounts, the one certainty to this point is that we are undeniably a “thinking thing.”
To put to rest the concept that everything we know is unreliable, by way of an imperfect God, one must go back to our ability to think, or further have thoughts. In his view, we are capable of countless thoughts and ideas of endless originality and ambition.
But in his mind, one thought stands above all others: the Idea of Absolute Perfection. To think of perfection, one must be able to think of an impossible thing, something with no flaws. For this thought to exist, it must have an origin.
Central to it needing cause is the Principle of Sufficient Reason or the idea that something cannot come from nothing, or in this case, an idea cannot exist without a cause. From his four potential places of origin, Descartes determines the only possible reason to possess an idea of absolute perfection is for a perfect God to have instilled it within us, as by his view the “perfect cannot come from the less perfect.”
For a Perfect God to exist, a deceptive god is impossible, and by way of that, the Deceptive God Doubt is put to rest. The knowledge that we exist, we are capable of thought, and that a Perfect God exists is untouchable by the Method of doubt.
To be able to perceive the world incorrectly is to be capable of perception, and to in turn respond to our sensory input by way of thought, inherently proving we are capable of thought and in turn exist. Whether we are in the waking world or the world of dreams, we are still existing, and to question our place in whatever surroundings may be is a self-defeating concept.
And the Deceptive God Doubt is, at least in the view of Descartes, fully put to rest based upon the foundation of our own undeniable existence and ability to think, the Idea of Absolute Perfection, and the Principle of Sufficient Reason.