Cartesian Dualism Challenged
In this paper, I will examine the issues of individuation and identity in Descartes’ philosophy of mind-body dualism. I will begin by addressing the framework of Cartesian dualism. Then I will examine the problems of individuation and identity as they relate to Descartes. Hopefully, after explaining Descartes’ reasoning and subsequently offering my response, I can show with some degree of confidence that the issues of individuation and identity offer a challenge to the Cartesians’ premise of mind-body dualism.
Before diving into a critical examination of these two issues, it would be wise to first discuss the basis of Descartes’ philosophy. Descartes begins his discussion of mind by first disregarding everything that he can call into doubt. After this mental cleansing, Descartes is left only with the maxim that ‘I cannot doubt that I am doubting.’ From this conclusion, Descartes states that some entity must be doing this doubting, and claims that this entity is his mind. The Cartesian mind has only one property: thinking. Consequently, Descartes establishes a distinction between mind and body. The two share no characteristics, as the body does not indulge in thinking, the mind’s solitary function. Further, mind and body are independent of each other; mind can exist even in the absence of body. At the same time, Descartes does not doubt that “the mind begins to think as soon as it is implanted in the body of an infant.” Yet the mind does not need the body to engage in introspection, the action of thinking about thinking. Only introspection is immune from illusion, confusion, or doubt. Information about the world outside of mind is prone to these hazards. We cannot conclude with certainty that other minds exist. Thus, the Cartesian is left to what I would dub a lonely existence: “Even if [a Cartesian] prefers to believe that to other human bodies there are harnessed minds not unlike his own, he cannot claim to be able to discover their individual characteristics. Absolute solitude is on this showing the ineluctable destiny of the soul. Only our bodies can meet.”
Now I will critically examine Descartes’ mind-body philosophy by addressing the issues of individuation and identity. First, I need to be clear about the issues I am addressing. In order to fully understand the problem of individuation, we need to focus on what the word individuation itself means. We can derive individuation from the Latin verb dîvîdo, meaning “I divide up” or “I separate into parts,” and also the prefix in-, which in this case means “into.” So, when we talk about individuation, we are talking about a state wherein an object can be separated or isolated from other objects: I can individuate Brown University sweatshirts from Rhode Island College sweatshirts based upon my observation of the insignia on them. Specifically, I am concerned with how I can distinguish minds from each other.
Strawson articulates the need for this distinction in his discussion of what he labels “the central difficulty in Cartesianism.” Strawson argues that if we want to talk about individual items—minds, bodies, computers, baseball cards, bananas, or practically anything—we must first understand the difference between one of that item and two of that item. In other words, to talk about an individual, you have to be able to count the individual. However, Cartesian philosophy does not allow for counting minds. The only mind you can know about is your own. Through introspection, I may be able to conclude that I am a thinking thing myself, much like Descartes did, but I cannot tell if the girl sitting at the computer next to me has one mind, three minds, seventeen minds, or even no mind at all. Thus the Cartesian cannot individuate minds. Strawson finds this fact problematic for the Cartesians, as the Cartesian “wants his doctrine to have the consequence that a perfectly ordinary man… has just one soul or consciousness which lasts him throughout.” Anti-Cartesians like Strawson have no such difficulty as they hold to the principle that one person houses one mind: If I can count two people in a room, I can necessarily conclude that two minds are present as well. When Descartes enters that same room, he is unaware of how many other minds share his company. Already we can see that the problem of individuation is a threat to the heart of Cartesian dualism.
Next I will turn my focus to the issue of identity, which holds a similar problem for Descartes. We can trace identity back to the Latin îdem, which means “the same.” Consequently, my discussion of identity will involve the problem of how I can determine that something is the same as itself. On the surface, you might think that such an investigation is rather frivolous. But consider the following problem: Am I the same person as the five-year old girl who used to watch “Sesame Street” and “Mr. Rogers’ Neighborhood,” was afraid to ride a bike without training wheels, and struggled with basic arithmetic? Surely, I’m not literally the same little girl, but at the same time something tells me that I am still the same Noelia today that I was then.
Strawson argues that, in addition to knowing how to count individual minds, we must also have the ability to “know how to identify the same item at different times.” The principle of identity is essential to guaranteeing that only one mind is associated with only one body, the doctrine that Strawson says is central to Cartesian dualism. Working under a Cartesian paradigm, you cannot determine that minds are the same over time in the same way that we, as I showed in my earlier example, consider bodies the same. Strawson argues that even if a Cartesian claims to be directly experiencing his mind through introspection and therefore has no need of explaining the identity of his mind, he still cannot rule out the possibility that a thousand different minds may occupy him during the next moment. As with individuation, Strawson and his fellow anti-Cartesians can correctly identify minds in the same manner that I identified myself as the same girl I was 9 years ago. Those operating under Descartes’ philosophy cannot identify the same mind over time, and consequently cannot speak “coherently” (as Strawson puts it) about mind.
Using Strawson’s analysis of Descartes as a guide, I have attempted to demonstrate how two issues—individuation and identity—threaten to dismantle Descartes’ philosophy of mind-body dualism. I have stood behind the anti-Cartesian argument that in order to associate one mind with one body—which Strawson claims is a vital principle to both Cartesians and anti-Cartesians—we must think of mind as something dependent on a person and not as something separate altogether, as Descartes would argue.