The Imperative Mood and Immateriality
I think James Ross’s Immaterial Aspect of Thought offers one of the most powerful counter-arguments to physicalism. That said, the argument is difficult to grasp. Edward Feser has an article that unpacks the argument a bit more, and some blog posts on the argument, which can be found here. Also, I think this post by Rocket Philosophy does a good job explaining the relevance of Kripkenstein’s quus to Ross’s argument.
Part of the reason that this argument is difficult is because we have to be clear on what terms like “determinate” and “formal” mean. When I’ve tried to explain this argument to others, I’ve emphasized the ways in which formal thinking is truth-preserving in all relevant cases. But my interlocutors often counter with the fact that we can malfunction in our calculations just like calculators, and more often than not we do! They take this to be evidence that we, like the calculator, simulate adding as best we can with the hardware we have, i.e. the brain. My objection to this is that a simulation cannot properly assess when a malfunction has occurred, but we often catch our own mistakes. Furthermore, we are capable of recognizing when a calculator fails to preserve the truth of some function in a relevant case, i.e. when it malfunctions. But a calculator could not recognize that its processes cohere with quadding rather than adding. Should two calculators take in the same input and provide different output, neither calculator could adjudicate over the matter. They could only disagree over what physical processes cohere with adding and which with quadding.
I think there may be a more straightforward proof of the immaterial aspect of thought, and it involves the is/ought dichotomy. The argument is as follows:
P1. No physical processes are processes that contain stages literally expressible in the imperative mood.
P2. Some mental processes are processes that contain that stages literally expressible in the imperative mood.
C1. Some mental processes are not physical processes.
A justification of the premises:
P1: All physical processes are matters of fact, and all matters of fact are about what is the case, and so must be expressed by the indicative mood. I say “literally expressible” to avoid the possible objection that one might use the imperative mood in a metaphorical sense, as in saying something like, “the sun ought to rise.” A computer programmer might object by saying that imperative programming is commonplace and computer programs are physical processes containing stages expressible in the imperative. At best, those stages involve the mental processes of the computer programmer who thinks, “if the program receives this input, it should provide that output”. The programmer then utilizes her knowledge of causal relationship between the software and the hardware, and the hardware with itself, so that it behaves according to the way she thinks it ought to behave, that is, given the ends the programmer has in mind. The computer program itself is fully described and explained according to descriptive physical laws, without reference to the normative logical laws or the practical reasoning employed by the programmer. When we think that a program issues and follows commands, we are speaking metaphorically. The program isn’t literally “oughting” its way through the command lines.
P2: Some mental processes contain stages that are normative. For instance, formal thinking is normative in that it appeals to rules so as to preserve truth. Likewise, moral reasoning involves an appeal to normative rules that preserve goodness. So a certain stage in a mental process could be literally expressed in the imperative mood. A person might express a certain stage in a mental process as “I shall conclude with the consequent of this conditional, since I have affirmed the antecedent” and so engage in the formal processes of modus ponens, or he might think “I ought to stop that mugging from happening” as part of a mental processes whereby his mind resolves to apprehend some villain and restore justice. A physicalist could object that one might be able to express all mental processes in the indicative, that is, with the appropriate adjustments, say, by burying all imperative verbs in noun-phrases, e.g. “the thought that I ought to stop the mugging from happening is occurring in my mind.” But the ability to avoid the imperative isn’t sufficient to avoid the conclusion. My argument runs not only if certain mental processes contain stages that can only be expressed in the imperative, but if such processes are possibly expressed in the imperative. Put simply, it isn’t possible to express physical processes in the imperative, at least if the expression is literal.
Implications for freedom of the will: The physicalist might be tempted to think that mental processes can only be metaphorically stated in the imperative, but the thought process itself should be literally expressed in the indicative, even if the content of those thoughts are expressed in the imperative mood. This naturally leads to the sort of determinism that causes the libertarian to recoil in horror. And the libertarian can hardly be blamed for such a reaction! For the determinist treats the normative content of thoughts as a mere epiphenomenal feature of the thought. The thought processes themselves are extrinsically determined by all of the physical facts involved. The libertarian, on the other hand, believes that the agent contributes uniquely to the causal nexus by willing to adhere to certain normative principles, that is, by allowing her apprehension that she ought to follow those principles to be part of the causal process by which she acts. I would suggest that agent causation can be understood best if one accepts that certain stages of the mental process can be expressed in the imperative mood. This is because mental processes can have genuine normative features, while physical processes cannot. If a mental process includes the apprehension of normative principles such that the apprehension is an actual part of the process (and not an epiphenomenon of the process), then an agent genuinely reason validly, i.e. with formal processes that preserve truth in all relevant contexts. For, to reason validly is not merely to accidentally accord with the formal process of a valid deduction. A process that is “accidentally valid” is just a simulation of validity, since the process of a valid deduction doesn’t just happen to be truth preserving by some coincidence of the physical laws. So to deny that we really reason validly is to undercut any sound argument in favor of determinism. Hence determinism is viewed as self-defeating. Why should I follow the reasoning of someone who concedes that his reasoning process is no more truth-preserving than the processes by which my Mr. Coffee brews my morning cup. The process that Mr. Coffee undergoes has nothing to do with truth preservation. Even if we decide to the coffee grounds stand for “1”, the water for “2” and the coffee that drips out of the machine as “3”, we can’t say that the coffee machine genuinely adds. It merely undergoes processes that we anticipate through induction. We can assign values to the physical components that the coffee-maker predictably modifies, declare by fiat that the modification is some function, and then use the coffee maker as a rudimentary calculator to help us track our own thinking processes (we just have to remember that grounds are a symbol like “1,” water is a symbol like “2,” and coffee is a symbol like “3”).
Daniel Dennett famously argues that religious beliefs originate in our HADD (hyperactive agency detection device). That is, we are evolved to attribute agency to any given phenomenon, whether it is the wind blowing a branch, or a thunder-clap. Ironically, I think it is physicalism that is a result of HADD. But it happens in three stages: 1) the physicalist falsely detects agency in a calculator, 2) the physicalist realizes that the calculator can be completely explained through physical processes, 3) the physicalist concludes by analogy that his own agency can be completely explained through physical processes. Calculators don’t have libertarian freedom, but they can add just like the physicalist without the need of such mystical freedom, or so the physicalist presumes.
If the determinist is correct, the processes by which she arrived at the conclusion contained no normative principles. However, this is why the libertarian says that the determinist abandons morality. The alternative view suggested here is that agent-causation occurs when a mental process becomes normative, which is to say that the normative aspects of thought feature as a genuine part of a mental process. But then agent-causation is not reducible to a physically determined process. To return to an earlier point, when I correctly perform a mathematical operation, I sense my own freedom and ability to take a truth-preserving function and choose to have that function preside over my thoughts. When I make a mistake in mathematics, I realize that my freedom is limited and constrained at times. I think about how I must have failed to remember the proper rules, or forgot which numbers I was dealing with, or lost focus about what I was doing, and so on. But that works well with my own theory of mind arising out of hylomorphism, for I do think that memories are located in the brain, and that there is two-way causation between the physical aspects of the mind and the immaterial intellect. The ability to be free is not a guarantee that I will always act freely, nor is the ability to reason in truth-functional ways a guarantee that we will always think validly. We can make mistakes. But it is our ability to recognize and learn from our mistakes along with our desire to avoid them that makes us more than just physical.