The Cogito argument

René Descartes contrived his famous Cogito argument as a stage with in his ontological argument for the existence of God.

Descartes claimed that he had cast all that he had previously believed into doubt before examining what remained. The argument runs that even if God has deceived him by placing thoughts in his mind, the mere fact of his being deceived means that something capable of being deceived must necesserily exist.

"But how do I know that there is not something different altogether from the objects I have now enumerated, of which it is impossible to entertain the slightest doubt? Is there not a God, or some being, by whatever name I may designate him, who causes these thoughts to arise in my mind ? But why suppose such a being, for it may be I myself am capable of producing them? Am I, then, at least not something? But I before denied that I possessed senses or a body; I hesitate, however, for what follows from that? Am I so dependent on the body and the senses that without these I cannot exist? But I had the persuasion that there was absolutely nothing in the world, that there was no sky and no earth, neither minds nor bodies; was I not, therefore, at the same time, persuaded that I did not exist? Far from it; I assuredly existed, since I was persuaded. But there is I know not what being, who is possessed at once of the highest power and the deepest cunning, who is constantly employing all his ingenuity in deceiving me. Doubtless, then, I exist, since I am deceived; and, let him deceive me as he may, he can never bring it about that I am nothing, so long as I shall be conscious that I am something. So that it must, in fine, be maintained, all things being maturely and carefully considered, that this proposition (pronunciatum) I am, I exist, is necessarily true each time it is expressed by me, or conceived in my mind.[ L][ F]"[M2]

The Discourse on Method was written in French, and there Descartes used the phrase, "Je pense, donc je suis." Descartes decided that this phrase could be misleading because it implied that he was appealing to an inference, so he changed the phrase to "I am, I exist" ("the first certainty") so as to avoid the term "cogito" in the later Meditations.

There have been a number of criticisms of the Cogito argument.

Quo Vadis?
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mind-body

From Cartesian dualism to Spinoza’s dual-attribute monism, Descartes’ and Spinoza’s arguments share some concepts while differing in significant ways concerning the relationship between mind and body. Descartes conceived of mind and body as separate, while Spinoza viewed mind and body as two attributes (aspects) of a single essence.

Descartes’ primary objectives in Meditations were to argue for the existence of God and for the possibility of the soul’s immortality. In The Ethics, Spinoza intended that his arguments correct what he perceived as the main difficulties in Descartes’ philosophy – the potential paradox of infinite division of finite dimension, the conceptualization of God, the mind-body problem, and the question of free will.

It is worth first noting that Descartes and Spinoza held different views of God. For Descartes, God was both his creator and the creator of his supposedly innate idea of God. For Spinoza, God is not his creator, but instead equates to the totality of Nature. Spinoza views God/Nature’s essence as existence, and God/Nature as a single substance with two basic attributes – substance and thought. Spinoza proposes that God/Nature’s attributes generate an infinite number of existent or potentially existent components, including human minds and bodies.

Descartes expanded on the Cogito argument, “Thinking is another attribute of the soul; and here I discover what properly belongs to myself. This alone is inseparable from me. I am—I exist: this is certain.” Descartes claims that the essence of his individuality lies in his soul, his conscious mind, and not in his body, “I am not the assemblage of members called the human body.”

Descartes invested in two distortions for the sake of his argument–that ideas are more clear than sensations, and that the mind and body are distinct. Descartes identifies the pineal gland as the site of the inexplicable interaction between mind and body–he probably chose the pineal because it sits at the base of the brain.

Descartes’ mind-body dualism enabled him to claim both that God (author of Descartes’ innate idea of God) exists and that the soul persists after the death of the body. He claimed that mind and body could exist separately, but that the mind was tethered to the body during the body’s lifetime—convenient!

Spinoza responded to Cartesian mind-body dualism by countering that the mind knows of its own existence only through the body, “The human mind has no knowledge of the body, and does not know it to exist, save through the ideas of the modifications whereby the body is affected.” That is, the mind perceives the body through sensations that originate in the body. In essence, Spinoza is claiming that the mind perceives the body only through changes in the body, and we perceive external objects through their impacts upon our sensory organs – sight, sound, touch, taste, smell, and motion.

To Spinoza then, thought is simply a modification of the body. In a sense, he was sufficiently correct for a reawakening of interest in his ideas amongst those currently ‘meditating’ on how the brain constructs consciousness through its physiological processes. (Neurologist Antonio Damasio is author of Looking for Spinoza: Joy, Sorrow, and the Feeling Brain)