V. The Argument from the Unity of Consciousness
Consider once again the inference “All men are mortal, Socrates is a man, therefore Socrates is mortal.” Now if there is one entity, namely me, that has all these thoughts, then it might be supposed that we have a rational inference here. If Bill has the thought “All men are mortal,” and Dennis has the thought “Socrates is a man,” and I have the thought “Socrates is mortal,” then we have a problem. No one person has actually performed the inference, and so the inference has not been performed at all.
Hasker, who has been both one of the chief proponents of the Argument from the Unity of Consciousness and the Argument from Reason, nevertheless thinks that there are separate arguments, and that the argument from the unity of consciousness should not be counted among the arguments from reason. Carrier thinks the argument is really an argument from consciousness rather than an argument from reason, and he thinks that in the last analysis what is plausible in the arguments from reason is simply the argument from consciousness. As Hasker put it, “The issue of unity of consciousness, after all, applies to conscious states that are in no way concerned with reasoning, including the states of sentient beings incapable of reason.”
True enough. But some people, confronted with the problem of the unity of consciousness, attempt to show that this unity is an illusion of some kind. I have in mind Dennett’s “multiple drafts” model from Consciousness Explained, and other theories like it. According to Susan Blackmore,
Each illusory self is a construct of the memetic world in which it successfully competes. Each selfplex gives rise to ordinary human consciousness based on the false idea that there is something inside who is in charge.
Or Steven Pinker, who writes,
There’s considerable evidence that the unified self is a fiction—that the mind is a congeries of parts acting a synchronously, and that it is only an illusion that there’s a president in the Oval Office of the brain who oversees the activity of everything.
Now if this is really true, if there is really no one individual who thinks the thoughts we think, then it follows straightforwardly that no one performs any rational inferences, including the rational inferences that have been used to reach the conclusion that the unified self is a fiction.
Now a philosophical naturalist can be a fictionalist about all sorts of things, but he cannot be a fictionalist about the sorts of inferences scientists make. So the Argument from Reason comes to the aid of the Argument from the Unity of Consciousness, and block the "eliminativist" response with respect to the unity of consciousness.
Kant argued, in the Second Paralogism
Every composite substance is an aggregate of several substances, and the action of a composite, or whatever inheres in it as thus composite, is an aggregate of several actions or accidents, distributed among the plurality of substances. Now an effect which arises from the concurrence of many acting substances is indeed possible, namely, when this effect is external only (as, for instance, the motion of a body is the combined motion of all it parts). But with thoughts, as internal accidents belonging to a thinking being, it is different. For suppose it be the composite that thinks: then every part of it would be part of the thought, and only all of them taken together would be the whole thought. But this cannot be consistently maintained. For representations (for instance, the single words of a verse) distributed among different beings, never make up a whole thought (a verse) and it is therefore impossible that a thought should inhere in what is essentially composite. It is therefore possible only in a single substance, which, not being an aggregate of many, is absolutely simple.
A formalization of the argument, which is developed in William Hasker’s The Emergent Self, goes as follows:
1. I am aware of my present visual field as a unity; in other words, the various components of the field are experienced by a single subject simultaneously.
2. Only something that functions as a whole rather than as a system of parts could experience a visual field as a unity.
3. Therefore, the subject functions as a whole rather than as a system of parts.
4. The brain and nervous system, and the entire body, is nothing more than a collection of physical parts organized in a certain way. (In other words, holism is false).
5. Therefore, the brain and nervous system cannot function as a whole; it must function as a system of parts.
6. Therefore, the subject is not the brain and nervous system (or the body, etc).
7. If the subject is not the brain and nervous system then it is (or contains as a proper part) a non-physical mind or “soul”, that is, a mind that is not ontologically reducible to the sorts of entities studied in the physical sciences. Such a mind, even if it is extended in space, could function as a whole rather than as a system of parts and so could be aware of my present visual field as a unity.
8. Therefore the subject is a soul, or contains a soul as part of itself.
Hasker’s example is the synchronic unity of being aware of my visual field, but in rational inference we find a diachronic unity; the inferring subject, who holds the premises of the argument in mind and draws the conclusion from them.
Now it will not do to simply point out that the brain is a highly complex system that is interconnected functionally and has billions of neurons. A genuine physical system is a system whose properties must be “summative” properties of its proper parts. If that is what a brain is, then no matter how complex it is, it is a set of parts.
A braking system of a car, a nutcracker, and even a chess-playing computer are all systems whose operations are the sums of the operations of their proper parts. Sometimes human beings are able to provide a framework of meaning for these objects that, if taken literally, would attribute to the system characteristics that they lack individually. But in human consciousness we find a subjective unity.
Carrier responds to this argument by sayingBut the point is the same: just as a collection of cells can organize and cooperate into a body that can walk—even though no one of those cells can walk at all or even has legs, much less the other needed organs, like hearts and lungs—so also can a collection of brain systems organize and cooperate into a mind that can think. And it does this by producing the virtual appearance of a singularity of consciousness, just as it produces the mere appearance that unified patches of color exist—when in fact only streams of various distinct particles exist.
But I am not talking about a unity of function that can exist in a braking system, I am talking about a unity of perspective experienced by the thinking agent itself. When a person infers “Socrates is mortal” from “All men are mortal” and “Socrates is a man,” that person infers the conclusion from his own perspective. There are truths that we know from a first-person perspective that cannot be known from any other perspective. For example, the truth that “I am Victor Reppert” is significant from my own perspective that cannot be discovered from a physical perspective. By taking an outside, third-person point of view, something is invariably lost.
It seems to me that Carrier, like Blackmore and Pinker, has fallen back on the fictionalist view of the unity of consciousness. But this position, I maintain, undermines rational inference.