I’ve written a few articles on AI – it is a fascinating topic. I have defined three stances in regards to the possibility of AI: The Platonic Stance, Weak AI, and Strong AI. I argued, successfully I think, that Weak AI is the most tenable position. I argued for this using John Searle’s Chinese Room argument and Godel’s Theorem. While I was writing these articles, I was constantly reminded of the intimate relationship between the debate over AI and the Philosophy of Mind. Each stance on AI is directly related to the ever-raging debate in the Philosophy of Mind concerning the mind/body problem. I thought it might be helpful to expound upon three different approaches to that problem and how they relate to the three stances on AI. Since the topic is so broad, I decided to parcel the discussion and write three different articles. Part One will address Descartes and The Platonic Stance.
Descartes contends that the mind is an immaterial entity, completely divorced from the material body. Characteristics of immaterial substances, like the mind, are distinct from those of material substances, like the body. Material substances are described in strict mathematical terms and their only properties are those of shape, size, position, motion, and number. Immaterial properties, however, possess none of these properties and only have one attribute: conscious intelligence.
These strong and controversial conclusions Descartes deduced in his, arguably, seminal work Meditations on First Philosophy. In the Second Meditation, Descartes “introduces a conception of the mind as defined by the contents of conscious thought” (89). Descartes asks us to imagine that we are under the control of an evil demon. This demon is omnipotent and hell-bent on ensuring our continual deception. He has control over our memories, our sense perceptions, and our faculties of reason. Everything we remember, see, hear, taste, touch, smell, and every deduction we make is nothing more than an illusion created by this evil demon. Descartes’ purpose with this thought experiment is to ask if, under these extreme circumstances, any belief could remain tenable, cogent. Is there anything we could still believe to be unassailably true? Descartes asserts that the statement “I exist” is such a belief. After all, in order to possess a belief, I must exist. I possess the belief I exist. Therefore, I must exist. Essentially, this is the infamous “I think, therefore I am” argument. And what is this thing that thinks? It is a thing that “doubts, understands, affirms, denies, wills, refuses, and also imagines and senses” (67).
In the Third Meditation, Descartes provides us with the general rule that “whatever is clearly and distinctly perceived as true is always true” (89). The Sixth Meditation makes the claim that “the idea of physical objects extended in space is clear and distinct as it is understood through the sciences of geometry and arithmetic” (89).
These three claims are then assembled to make the argument for Cartesian Dualism. The argument is as follows:
1. Anything that I can clearly and distinctly understand can be created by God exactly as I understand it. So if I can clearly and distinctly understand one thing apart from another, this is enough to make me certain that two things are distinct.
2. I can form a clear and distinct understanding of my own existence as depending on nothing more than the fact that I think, and hence (from Premise 1) it follows that nothings belongs to my essence except thought.
3. I also have a clear and distinct understanding of physical bodies (including my own) simply as extended matter, without possessing any thought.
4. Hence, I (or my soul) am distinct from my physical body and can exist without it (89-90).
“The particular state of affairs Descartes has in mind is the independent existence of mind and body. By definition two things are distinct (that is, there are two things, not one) if each one can exist when the other doesn’t. Descartes’ idea is this: if he can conceive clearly and distinctly of the mind existing without the body, and the body without the mind, then these must be real possibilities, hence they must be two distinct things.” (90)
This is the foundation for what I have referred to as the Platonic Stance, and maybe I should have dubbed it the Cartesian Stance. Either way, proponents of this particular stance contend that AI will never be achieved because the mind and body are two distinct entities, each with distinct sets of properties. The mind is immaterial; the body is material. Properties of material objects can be understood, replicated, and reproduced through scientific endeavors and advances. Properties of immaterial things, cannot. The immaterial, as far as strict Cartesian Dualism is concerned, is relegated to a nebulous realm of the mystical, forever eluding our understanding.
There are, however, many problems with Cartesian Dualism. Problems that should not be ignored.
Firstly, Descartes argues that he can doubt everything else about his essence except for his thoughts, therefore thought is his essence. This is a fallacy of ignorance. It is a logical leap from the fact that we are only aware of one thing’s existence, to the conclusion that only one thing exists.
Secondly, there is the problem with Descartes general rule. This problem is commonly referred to as the Cartesian Circle. The general rule states that whatever can be clearly and distinctly perceived is necessarily true. The rule takes as an assumption that God is not a deceiver. Why? Because Descartes can clearly and distinctly perceive that God is not a deceiver. Effectively, he is using his conclusion as a premise, thereby employing circular reasoning or the fallacy of begging the question. The criterion of clear and distinct perception depends upon the existence of a non-deceiving God, which in turn depends upon the criterion of clear and distinct perception.
Lastly, there is the insuperable interaction problem. How does a material substance interact or influence an immaterial substance; and how does an immaterial substance interact and influence a material substance? Of the three objections I have given, the interaction problem has had the greatest influence on subsequent philosophers rejecting Cartesian Dualism.
Descartes was and is an important figure in Philosophy. He was a revolutionary thinker. I greatly respect him for his contributions. However, I do not find his arguments to be particularly convincing, cogent, or remotely endorsable. There are still a few Cartesians lingering in our midst today. They argue vehemently against the advent of AI. And they have held their ground in the face of compelling arguments to the contrary. And while they may be immune to sound logic and reason, time will ultimately force them to adopt a different perspective. Advances in the fields of neuroscience and physics (notably quantum physics), will force the most adamant Cartesian to admit defeat.
Functionalism and Strong AI
Mortan, Peter A. A Historical Introduction to the Philosophy of Mind. Ontario: Broadview Press Ltd, 1997.