Darwin + Hume = Daniel Dennett
Tufts University philosopher Daniel Dennett's intellectual career has been spent trying to extend the Enlightenment project of putting philosophy and morality on a scientific and naturalistic basis. His newest book, Freedom Evolves tries to answer the age-old question: Can there be freedom and free will in a deterministic world? Dennett is trying to update David Hume in the light of Darwin's theory of evolution. In doing so, he provides us with fascinating new ways to think about the meaning of choice, the value of morality, and how the evolution of the human brain and its capabilities has made us more free.
As per Hume, we never see the "cause" of an event; we only note the conjunction of two events in time and space and infer that one must have caused the other. As Dennett points out, life depends on just such regularities. If all things really were random, then the complicated processes that produced life could not have arisen. Natural selection shapes organisms so that they can respond to and exploit the regularities in their environments.
Early in evolutionary history earthly organisms developed some ability to avoid dangers and seek benefits. For example, amoebas and bacteria use chemotaxis—the ability to change their direction of movement in response to concentrations of specific chemicals—thus enabling them to avoid toxins and to find food. On this rudimentary ability to sense and avoid harm and seek benefits, natural selection has erected ever-higher levels of freedom of choice in earthly organisms, according to Dennett. For example, complex organisms, like birds, are endowed with long-range senses like eyesight and hearing which help them avoid far-off dangers and take advantage of distant opportunities.
So every animal that lives gets to choose. But there is a big difference between other animals and people. Amoebas and birds and most other animals are "situation-action machines." They are endowed by natural selection with a more-or-less fixed repertoire of behaviors that tell an organism, "In situation A, do action B." Amoebas have fewer choices, while birds have more.
On the other hand, people are "choice-machines." That means that we generate our own reasons for doing something. Unlike birds or amoebas, our reasons are not hardwired by natural selection, although our capacity to reason is. Dennett argues that it is this natural capacity that allows people, of all living beings on the earth, to weigh and justify to themselves and others different courses of action.
But is this capacity to reflect and choose "real" free will?
Free will is often thought of as a kind of uncaused cause that people generate within themselves. At the moment of decision, a kind of miracle occurs and a choice between alternatives is made. As neuroscience advances we have begun to understand that human brains contain many subsystems, most of them unconscious, all which are amenable to being described in terms of their physical characteristics, leaving less and less space for miraculous occurrences. Still, some philosophers and others want to argue that free will, an ability to make an uncaused choice, must somehow lurk in phenomena like quantum indeterminacy. Dennett shows these attempts to bolster miraculous notions of free will are incoherent.
How? There is no way for us to distinguish between a determined and undetermined choice in any case. Assume that a jilted wife is at the precise moment where she will decide either to run over her two-timing husband with her Mercedes Benz or not. Look at two cases. In the first, at the crucial moment a random number jumps up from the indeterminate quantum, hits the right neuron and inclines her to floor the gas pedal. Or secondly, assume that a pseudo-random number (which is obtained from a table of such numbers generated by a deterministic computer) is fed into the same neuron and she floors it.
Neither the jilted wife nor an observer would be able to distinguish between the two cases, yet one is indeterminate and the other determined. Besides, in what sense would her decision have been "free" in any case? The random choice is no freer than the determined choice. It's just random. As one wag put it: "Either our actions are determined, in which case there is nothing we can do about them, or our actions are random, in which case there is nothing we can do about them."
If driving over her husband were an uncaused choice, what possible reason would society have for punishing her? Some might reply, "We're not worried about uncaused choices, but self-caused choices. She chose to run over him." But ask yourself: What would a self-caused choice look like? How would you describe that concept scientifically? Where in the brain would you look for it? After all, human brains and selves are never seen one without the other. Selves, whatever they are, occur in human brains. Dennett argues that a self is a metaphor for our bodies and brains as they exist over time that provides each of us an outlook on what is going on in our own brains and in the brains of others. Selves, according to Dennett "wouldn't exist if it weren't for the evolution of social interactions requiring each human animal to create within itself a subsystem designed for interacting with others. Once created, it could also interact with itself at different times." A self then is an efficient shorthand subsystem devised by our brains to monitor and interact with our own intentions and the intentions of others.
"Actions are, by their very nature, temporary and perishing; and where they proceed not from some cause in the character and disposition of the person who performed them, they can neither redound to his honour, if good; nor infamy, if evil," declared Hume. Or as psychologist and philosopher William James put it: "If a 'free' act be a sheer novelty that comes not from me, the previous me, but ex nihilo, and simply tacks itself on to me, how can I, the previous I, be responsible?" So whether the wronged wife should be punished or not doesn't depend on indeterminism or determinism. It depends on her society's moral rules.
In fact, in everyday practical moral reasoning, we expect people's choices to be the result of their previous upbringing, their moral character. Moral character can be thought of as a set of predictable responses to ethical choices. We know that people develop moral beliefs and habits through life experiences. Our moral reflexes are honed through watching and hearing about which actions are rewarded and which are punished; we learn to be moral in much the same way we learn language.
Just as we know that a caged bird is not free, we also know that a handcuffed person or one being prodded by a pistol-wielding kidnapper is not free. "Liberty is universally allowed to belong to every one who is not a prisoner and in chains," writes Hume. Dennett, like Hume, points out that in moral discourse, the real question we confront is not between caused and uncaused choices, but between coerced and un-coerced choices. If someone had been holding a gun to the jilted wife's head and ordered her to run over her husband, we would not blame her for her actions.
However, if a person does something without being coerced, she chose to do it and she deserves whatever praise or blame her action merits. This view is well summed up with philosopher Alfred Mele's notion of a Default Responsibility Principle: "If no one else is responsible for your being in state A, you are." Our everyday practical moral reasoning allows us to figure out which people are morally responsible and which are not. For example, children are held to a lesser standard because they function more like situation-action machines than choice machines. On the other hand, we hold jilted wives who run over their unfaithful husbands accountable because they know or should know that that is the wrong thing to do.
Dennett further shows how Darwinian processes have harnessed selfish genes and self-interest to fashion human morality. Our ability to foresee consequences at much longer range in space and time enables us to quell immediate selfish desires in order to benefit from living in a broader society with a division of labor. We learn that in general the best way to succeed in life is by appearing to be good so that our fellow human beings will trust us and want to truck and trade with us. And the easiest way to appear good is by actually being good.
Dennett also points out that human freedom is dramatically expanding. Birds, like most earthly organisms, live as their ancestors did, and their range of choices is determined by the stately processes of biological evolution. People, on the other hand, are no longer tethered to evolutionary change. Language and culture, especially modern science and technology, enable us to dramatically increase the range of our choices. If you don't believe it, just think about the much smaller range of opportunities open to Americans 100 years ago.
As our understanding of our genes and brains increases, instead of limiting our freedom, it will dramatically increase it. We will be able to prevent and cure more diseases, improve our social institutions, and even enhance human capabilities. We defend freedom, especially political freedom, because, among other things, it enables people to make better and better choices over time. To whatever extent we were ever at the mercy of our genes, we no longer are. Instead our genes are now at the mercy of our brains.