Compatibilism holds that free will can coexist with determinism. But what exactly is determinism? The term is sometimes used casually and with somewhat fluctuating meanings. Different versions (or aspects) constrain free will theories to quite different degrees.
I was introduced to determinism during one Christmas break, when I read Will Durant’s The Story of Philosophy to get some background before my first college philosophy course. As I recall, Durant said determinism was based on a vision of the universe as a giant machine, cranking along as it inevitably must. The categories of actual and possible overlap 100%, which means that everything that happens is the only possible thing that could happen. My naive undergraduate mind didn’t see much room for free will in that scenario. If anything, getting rid of foofy notions like free will seemed to be precisely the point.
More recently, Al Mele defined determinism in the Encyclopedia of Consciousness as “the thesis that the combination of a complete statement of the laws of nature and a complete description of the condition of the entire universe at any point in time logically entails a complete description of the condition of the entire universe at any other point in time.” Adina Roskies defines it in TICS as belief that “the state of the universe is entirely a function of physical law and the initial conditions of the universe.” The Big Questions in Free Will Lexicon of Key Terms (http://www.freewillandscience.com/wp/?page_id=63) defines it as “The thesis that a complete statement of the laws of nature together with a complete description of the entire universe at any point in time logically entails a complete description of the entire universe at any other point in time.”
I see up to three elements to these definitions, and different people may embrace them to different degrees. That could cause confusion and arguing past each other.
The three are pan-causality, reductionism, and predestination. With a nod to a classic Western movie, I think of them as the good, the bad, and the ugly. Let me comment on each and what it does to free will.
The simplest aspect of deterministic thinking says that everything is caused. This “gentle” aspect of determinism is not hard to swallow and may even be compatible with some randomness. I suppose it depends on what is meant by “causing,” but as far as I can tell that is simply a description of how one event or state leads to another. (Actually, in practice, multiple events or circumstances come together to create another; single-cause explanations are probably almost never correct. Every causal principle known to psychology ceases to operate above 200 degrees Fahrenheit, for example.)
Full-blown determinism, as indicated by the definitions I gave earlier, generally involves more than just pan-causality. Still, I have come to realize that many eminent scientists (including perhaps my sometime debating opponent John Bargh) understand determinism as no more than pan-causality, and so it is no wonder they are upset when people question determinism. To them, science is constantly “proving” determinism insofar as it furnishes evidence of causality. Hence it is helpful to consider a watered-down, gentle form of determinism that insists only on causality.
There are many types of causes. The causal principles one would invoke to explain why an electron changes its orbit might well bear no resemblance at all to the principles one would invoke to explain the international economic collapse of 2008. Meanwhile, pan-causality even allows for causes that operate in large systems, for causes that operate by changing probabilities, and for multiple possible outcomes in the future. I’m not sure what all causes have in common, except that some things lead to other things. New kinds of causes could even emerge. Natural law has presumably been there since the Big Bang, but still, there is no reason new causes couldn’t emerge, is there? Meanwhile, cultural laws are certainly more recent. Next year there will be new laws, unless all governments go on strike.
Pan-causality by itself seems not that hard to reconcile with many definitions of free will. Free will could be simply another one of the many different kinds of causation. Unlike billiard balls, electromagnetic fields, the laws of probability, gravity, and other sorts of causation, free will operates with a single agent who conceptualizes multiple possible future outcomes and chooses among them based on reasons that may include symbolism and meaningful calculations.
The formal definitions of determinism I quoted above refer specifically to natural laws. Cultural laws are not mentioned, even though they clearly have causal impact. (For example, traffic laws alter the trajectories of many molecules!) The only excuse I can imagine for failing to acknowledge cultural laws — and all other social, cultural, and symbolic causes of behavior — is that people may think that natural laws can fully explain them. This brings up the second element in notions of determinism, namely reductionism.
Reductionism is the belief that what happens on one level can be fully explained by events at lower levels, presumably all the way down to subatomic particles. To reductionists, your thoughts are entirely explainable as the results of chemical and electrical activity in your brain. Your brain is fully explainable as the result of biological causes, which in turn can be entirely accounted for by chemical reactions, which in turn are the results of molecular structure, and so on. Physics is the bedrock, the lowest level, to which everything else can be eventually reduced.
In physics, reductionistic views once prevailed, and physicists all comfortably assumed that eventually their work would be able to explain everybody else’s. The turning point was Philip Anderson’s classic article “More is Different,” in which he argued (and the field came around to agreeing with his view) that different kinds of causes operate at different levels. In particular, new kinds of causes emerge at different levels or scales. Today I doubt you will find many professional physicists who think the banking crisis of 2008 could ever be explained in terms of the exchanges of photons between protons and electrons.
To appreciate the problem, imagine a book that explained the Civil War in lower-level terms, by describing only muscle movements, say, or (below that) nerve cell firings, or chemical reactions, or the movements of subatomic particles. Not only would this style be cumbersome and inconvenient. I’m pretty sure that even someone who read the whole book wouldn’t be able to recognize it as a history of the Civil War. It would completely miss the point of the war and, more profoundly, would fail to explain the true causes of all the action. Some of these causes existed only at the level of large systems of shared understandings among groups of people.
I said earlier that some scientists may believe that pan-causality is constantly being proven by findings that show causation. How someone could sustain a belief in reductionism is much harder to say, however. Reductionism has been “proven” wrong locally countless times. With regard to patterns of human behavior, for example, as research marches on, things almost always turn out to be more complicated than initially surmised. Over time, as new data come in, theories generally become more and more complex, not simpler as reductionists would have us believe.
In any case, if one does embrace reductionism, free will is still plausible but loses much (as compared with mere pan-causality). Ultimately free will would have to be fully explained by subatomic processes, which means you can completely account for it in terms of the handful of variables that physicists use, such as each particle’s mass, charge, velocity, and so forth. Responsibility and justice are just chemical reactions, so to speak. So is free will in a reductionist’s worldview.
AND THE UGLY
If causality is the good and reductionism is the bad, predestination is the ugly.
Predestination rules out multiple possibilities and insists that everything that happens is the only thing that possibly could. The future is just as fixed in stone as the past. Everything you will ever say or do has already been scripted.
In the Lexicon, predestination is essential to the definition of determinism, since pan-causality is specifically said to be not enough for full determinism. It has to be possible to deduce the full state of the universe at any time if you know the full state any other time plus have full account of the laws of nature (and presumably if you have one super kickass computer.)
In a sense, predestination undermines some concepts of choice and agency. The agent is just a throughput. The literal meaning of choice is to select among possible alternatives, but the predestinationist insists there is only one possible outcome rather than multiple possible alternatives, so the agent’s belief in their multiplicity is fundamentally mistaken. The agent is doing something and being part in the causal chain. But the agent is not doing what agents by definition are supposed to do, namely exert control in the sense of choosing and steering among multiple possibilities, only some of which come true.
The athlete’s belief that he or she can influence or help cause the outcome of the game is correct, but the belief that he or she can change the outcome is wrong, according to the predestinationist. The fundamental essence of a game as having multiple possible outcomes is an illusion too, if you accept predestination.
SIZING UP THE COMPATIBILIST BEDFELLOWS
Compatibilism means that free will can coexist with determinism. But the good, the bad, and the ugly aspects of determinism are not equally congenial bedfellows for free will. You can have a vigorous and fascinating free will compatible with the gentlest form of determinism (ie, pan-causality alone). My sense is that purists (including the Lexicon) agree that pan-causation alone is not full-blown determinism. However, it is probably a popular version with the (wo)man in the street and other philosophically challenged folks, scientists included, and of course it is far more likely to be true than the more demanding versions that bring in predestination and/or reductionism.
Once reductionism and/or predestinationism climb into the bed, however, the scope for free will narrows dramatically. As a trio, the good, the bad, and the ugly will be hard for free will to satisfy and hard to live with. A free will that is compatible with them all looks to me more like a puppet government, or even just a puppet.
Help me out here, dudes! Can a free will find compatibilist happiness together with all three bedfellows?
Also, is there something that all causes have in common?