Despite this, Descartes argued that the faculties could not be a reliable source of information, since they occasionally provided false information. Additionally, since the actuality of suggestions based on sense is typically probabilistic, the recommendations are improbable premises when they are used as arguments. In this paper, I will clarify Descartes’ claim that knowledge obtained solely through sensations cannot be believed and that the basis of all knowledge is instead what he claims to be.
In his final and widely read book, Passions of the Soul, Descartes describes how various bodily movements cause commotions and interests to emerge in the spirit. He begins by outlining a few objective truths regarding the relationship between the mind and body. The complete psyche is present throughout the body and in all its components, but the “pineal organ,” a small organ at the center of the brain, serves as its primary location (Descartes, 1649). On what he means by “the entire brain in the entire body and the entire in every one of its parts,” Descartes is not entirely clear (Descartes, 1649). However, in Descartes’ day, this was not a particularly inventive way to illustrate the connection between the spirit and the body. The main issue was that a human body needs the heart to be truly human—a living human body as opposed to a corpse. Given Descartes’ illogical use of this expression, it becomes difficult to believe that he did so in the same way as his contemporaries.
Descartes continues, adding that all feelings depend on the nerves, which emerge as tiny filaments enclosed in tube-like films from the brain to the body’s outermost extremities. The “creature spirits” are the extremely fine materials these filaments skim (Descartes, 1649). This enables the strands to move freely, causing even the slightest movement anywhere in the body to result in growth in the area of the brain where the fiber is linked. Hence, strictly speaking, when a toe is struck, the pain only affects the mind, not the foot.
The human mind has intricate patterns and complicated ways of working. Finally, he discovered that describing one in terms of the other was impossible. The fact that the two could be defined independently of one another was sufficient for Descartes to treat them as separate things because he described a substance as something that does not depend on anything else for its existence.
References
Descartes, R. (1649). Part I. About the passions in general, and incidentally about the entire nature of man. In S. H. Voss (transl.) The passions of the soul (pp.18-49). Hackett Publishing Company, Inc.