The Mystery of Our Being: Limits of Causal Explanation?

In "The Mystery of Our Being," the famous 20th century physicist Max Planck asserts that there are limits to what science can explain. His view is of interest to us because he assumes that science is limited to causal explanation. The limitations arise in consideration of what he calls "freedom of the will":

What does Planck have in mind here? Why is he so concerned to exempt the ego, or self, from the laws of causality? We can understand what he's getting at by considering a deep problem, The Problem of Free Will and Determinism.

Here are some principles that all seem so obvious that it might not seem worth stating them explicitly:

PUC seems necessary for making the most basic sort of sense of what happens in the world. When the washing machine throws soapy clothes all over, we're not happy if the repair service says they can't discover the cause of the malfunction; but we'd reject as utterly preposterous a claim that the malfunction was not caused. Similarly, we may not expect to understand fully (or even partially) why one person murders another, but we'd find unintelligible the claim that the murder occurred for absolutely no reason whatsoever and without there being any cause at all.

R is a very weak claim. All that's required for its truth is that there be one instance in all of history of some person's performing some one action for which s/he bears moral responsibility. Of course, most of us believe something far stronger than R; we believe that much of the time people bear moral responsibility for their actions, even if we often have a hard time determining the exact nature and degree of responsibility.

The apparent truth of A is easiest to see in cases where what someone does is unavoidable. If your kidnappers drug you unconscious and then toss you out the third story window before they abscond to Rio with the $100 ransom, you're not to blame if you crush a passerby below the window - even if their death insures your survival. In such circumstances, you're no different from a rock thrown out the window and bear no moral responsibility for damage to what you hit. And just as unavoidability entails lack of moral responsibility, so, as a matter of simple logic, does moral responsibility entail avoidability.

Although each of these three principles seems to be a matter of common sense, we can prove that at least one of them must be false. The problem is then to find some rational basis for rejecting one of them, with the understanding that we're in a 'no win' situation. We can see that the principles are inconsistent by means of the following argument:

This is not offered as a proof that PUC is wrong: we could just as well have argued that if PUC and A are true, then R is false; or if PUC and R are true, then A is false. This argument is intended to show that PUC, R, and A are mutually inconsistent. So at least one of them must be false and the best outcome we can hope for is to minimize our inevitably large loss. Let's examine four possible solutions to the problem.

One possible solution is Hard Determinism: Every event is causally determined, and moral responsibility entails avoidability, so no one is ever morally responsible for anything. If there were any way to avoid the repugnant consequence of this view, we should surely take it. Nevertheless, some argue in its favor as follows:

The first premise is based on the belief that some day psychology will be a science and so will be able to give correct explanations for all of human behavior. The weak premise is (2). We may distinguish between two types of explanation. Causal explanation entails that human behavior is causally determined. But purpose-directed explanation need not entail that human behavior is causally determined. If purpose-directed explanation is a genuine alternative to causal explanation in not entailing causal determination, then it may have an important role to play in solving the Problem of Freedom and Determinism.

A second logically possible solution to the Problem is Indeterminism: At some time, some person is morally responsible for what s/he does, and moral responsibility entails avoidability, so some events are uncaused; for these uncaused events and their consequences we may be morally responsible. This view seems to be advocated by Existentialists, such as Jean-Paul Sartre, as well as by some who misinterpret the significance of probabilistic quantum mechanics.

The first premise simply restates part of Indeterminism, and the second premise is true by definition. The third premise is well illustrated by the case of "Crazy" Bob. Bob is an otherwise ordinary guy who, without cause, suffers occasional episodes of very rapid right arm extension. It is of course implausible that such uncaused events would occur, but Indeterminism embraces this possibility. During his first such episode, he happened to be passing a fellow pedestrian, whom he hit and knocked into the path of an unstoppable steamroller. Despite having been directly involved in the pedestrian's death, Bob is as much a victim of circumstance as the now defunct pedestrian - Bob's right arm went out for no reason whatsoever; he did not choose to extend it then, nor could anyone have taken precautions to prevent its extension since there was no knowing in advance that it might happen. Indeterminism nevertheless assigns blame to Bob. So this argument shows that Indeterminism is false.

Planck's Proposal: There are two ways to interpret what Planck says. On one reading, he's an Indeterminist, since he exempts minds from causal laws. If that's what he means, then, as the argument above shows, his proposal is wrong.

On another reading, he maintains that the material world is governed by causal laws, but the internal world of the self is governed by the "dictate of duty," of Categorical Imperative. The idea seems to be that just as laws of causality govern the material world, laws of morality govern the internal world of the self. But laws of morality say what ought to be, not what actually is, and so are useless in explaining what people actually do, and why their moral characters may change over time; to explain morally significant change, it seems that causal explanation is necessary. So on this second reading, Planck's proposal makes it impossible to explain moral change or to undertake moral education, an unacceptably high price for a solution that is supposed to 'save morality'.

A third possible solution, which is probably the most popular nowadays, is Soft Determinism: Every event has a cause, and at some time, some person is morally responsible for what s/he does, so we may be morally responsible for some unavoidable actions - those that are internally caused, and their consequences.

Soft Determinism is also called "Compatibilism" since is says that causal determination and moral responsibility are compatible (and so A is false). Soft Determinism owes us a clear and precise account of internal causation. Here are three attempts to define internal causation. Each must be tested against the claim at the heart of Soft Determinism: if an action is internally caused, then the person who performs it (the 'agent' of the action) is morally responsible for the action and its consequences.

An appealingly simple definition is

But this can't be right. Suppose that the Vegetabilist Liberation Front kidnaps and tortures you, imposing on you weird beliefs and desires by convincing you that the only way to make the world safe for your family and incidentally for Vegetabilism is to murder the chief lobbyist for the Florida Citrus Commission. If you carry out this heinous act, you'll be involved in something very bad. You have acted on beliefs and desires that did indeed motivate you, but you are not to blame. More generally, people can be 'brainwashed' into having beliefs and desires that are bizarre and out of character, and they may act on those externally imposed mental states, but surely it's the fault of those who tortured them that they act badly, and not the agent's fault, contrary to what the definition implies. So let's try stipulating that the relevant mental states are not imposed on the agent:

There are two objections to this definition, one minor and one major. The minor objection is that beliefs and desires are often not chosen at all: we simply find ourselves with them. This is particularly clear in the case of perceptual beliefs: when you open your eyes upon awakening, you don't choose to see the sunlight - you just do, and you believe thereby that it's sunny. The major objection focuses on the phrase of "freely chosen" - what, exactly does this mean? One possible meaning is that the choice is uncaused, but Soft Determinism holds that every event is caused, so that meaning is unavailable to it. Instead, what must be meant is that the choice is caused in a way that secures moral responsibility for the action, that is, "freely chosen" must mean that the choice was internally caused. But if that's what "freely chosen" means, then the definition is circular and hence useless. Another possible way around the 'brainwashing' problem is:

Unlike the second proposal, there's no implication that the beliefs and desires are uncaused, nor is there any apparent circularity. And the last part rules out brainwashing. Nevertheless, this definition is also open to counterexample. Suppose that Reliable Ralph, a lab assistant, is feeling very thirsty and sees what he reasonably believes is a beaker of distilled water on the lab table. His belief is well-justified since he's known the lab supervisor for years and knows her to be even more reliable than he is and especially careful not to leave anything dangerous around. So, he takes a drink from the beaker instead of going down the hall to the soda machine. Unfortunately, there was a glitch in the supervision and Ralph's just consumed a powerful hormonal extract that causes him to fly into a homicidal rage and to strangle the supervisor, who's just returned to the lab. As terrible as this is, Ralph's clearly not at fault. But the definition says he is. So the definition is wrong. And remember that we can't modify the last part of the definition to read "– and nothing compelled e's agent to have those beliefs and desires," since that would say in effect that the beliefs and desires were uncaused - an impossibility according to Soft Determinism.

Perhaps there's some other way to make good on Soft Determinism's promise of moral responsibility with causal explanation. But things don't look good.

So far, we've focused on causal explanation of human behavior (except for the brief mention of purpose-directed explanation above). But mightn't the problem be solvable with the proper uses of non-causal, purpose-directed explanation? Let's see.

The fourth possible solution to the Problem of Freedom and Determinism is the metaphysically radical view, Libertarianism or the Theory of Agency: Every event is caused, but some events are caused by the agent and not by any event; for these agent-caused events and their consequences we may be morally responsible.

Agency Theory is a radically different from any of the three preceding views (see chart below). They all maintain that causation is a relation between pairs of events ("event c causes event e"). According to Agency Theory, some but not all events are caused by other events ("event causation'); some events are caused instead by persons ("agent causation"). According to Agency Theory, agent-causation is involved in choices for which we may bear moral responsibility because, after all, we ourselves are the causes.

Contrasting Solutions to the Problem of Freedom and Determinism

Possible Solution	Principle of Moral Responsibility	Principle of Universal Causation	Principle of Avoidability	Kinds of Causation
Hard Determinism	Rejects	Accepts	Accepts	event only
Indeterminism	Accepts	Rejects	Accepts	event only
Soft Determinism (Compatibilism)	Accepts	Accepts	Rejects	event only
Agency Theory (Libertarianism)	Accepts	Accepts*	Accepts	event AND *agent

But the Agency Theorist should reject the third premise. She may reply that some acts may nevertheless be explained by being given a purpose-directed, rather than a causal, explanation. In this way, they may be rendered 'intelligible'. Here, it seems, is the 'natural home' of purpose-directed explanation taken as a genuine alternative to causal explanation. But there is a problem with taking it in this way, as we can see from an argument first offered by the philosopher C. D. Broad. I'll introduce it with an example.

Al has a problem with alcohol - he drinks too much of it. On ten successive Saturday nights, he attends a party at Ben's house with the usual set of friends and on the first nine nights, drinks himself into a stupor, though not before vomiting on the couch. Suppose that on all ten occasions, the event-causal forces acting on Al balance exactly: the forces inclining him to drink to excess are matched exactly by the forces inclining him not to drink to excess. According to Agency Theory, it is under precisely such circumstances when the agent himself can 'step into' the causal chain and (agent) cause one alternative or the other. So each of the first nine nights, when Al drinks to excess, he is the cause of his bad behavior. On the tenth night, Al 'gets his act together' and causes abstinence instead, with much rejoicing by Ben and others. According to agency theory, he is to blame for his behavior the first nine nights, and deserves praise for his moral reform on the tenth night. Ben and others wonder why Al got his act together on the tenth night, and not, say, on the fourth or the twelfth. What is the explanation for Al's moral improvement? It seems that Agency Theory precludes there being any answer to this natural question, "Why now?" To summarize:

Agency Theory seems to preclude there being any explanation for why a person acts one way at one time and another way at another time, with respect to moral choices.

This suggests that if we take purpose-directed explanation to be incompatible with causal explanation, in line with Agency Theory, we will be forced to give up any hope of psychological explanation in the cases where we want and need it most.

Is it possible that purpose-directed explanation is both not reducible to causal explanation and compatible with it? That's a good question - one that deserves an answer from anyone who wishes to explore Separation by Explanation's prospects more thoroughly.

Additional Sources

2000 David F. Austin

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