By Joshua Knobe
Imagine that tomorrow’s newspaper comes with a surprising headline: ‘Scientists Discover that Human Behavior is Entirely Determined.’ Reading through the article, you learn more about precisely what this determinism entails. It turns out that everything you do – every behavior, thought and decision – is completely caused by prior events, which are in turn caused by earlier events… and so forth, stretching back in a long chain all the way to the beginning of the universe.
A discovery like this one would naturally bring up a difficult philosophical question. If your actions are completely determined, can you ever be morally responsible for anything you do? This question has been a perennial source of debate in philosophy, with some philosophers saying yes, others saying no, and millennia of discussion that leave us no closer to a resolution.
As a recent New York Times article explains, experimental philosophers have been seeking to locate the source of this conundrum in the nature of the human mind. The key suggestion is that the sense of puzzlement we feel in response to this issue arises from a conflict between two different psychological processes. Our capacity for abstract, theoretical reasoning tells us: ‘Well, if you think about it rationally, no one can be responsible for an act that is completely determined.’ But our capacity for immediate emotional responses gives us just the opposite answer: ‘Wait! No matter how determined people might be, they just have to be responsible for the terrible things they do…’
To put this hypothesis to the test, the philosopher Shaun Nichols and I conducted a simple experiment. All participants were asked to imagine a completely deterministic universe (‘Universe A’). Then different participants were given different questions that encouraged different modes of thought. Some were given a question that encouraged more abstract theoretical reasoning:
In Universe A, is it possible for a person to be fully morally responsible for their actions?
Meanwhile, other participants were given a question that encouraged a more emotional response:
In Universe A, a man named Bill has become attracted to his secretary, and he decides that the only way to be with her is to kill his wife and three children. He knows that it is impossible to escape from his house in the event of a fire. Before he leaves on a business trip, he sets up a device in his basement that burns down the house and kills his family.
Is Bill fully morally responsible for killing his wife and children?
The results showed a striking difference between the two conditions. Participants in the abstract reasoning condition overwhelmingly answered that no one could ever be morally responsible for anything in Universe A. But participants in the more emotional condition had a very different reaction. Even though Bill was described as living in Universe A, they said that he was fully morally responsible for what he had done. (Clearly, this involves a kind of contradiction: it can’t be that no one in Universe A is morally responsible for anything but, at the same time, this one man in Universe A actually is morally responsible for killing his family.)
Of course, it would be foolish to suggest that experiments like this one can somehow solve the problem of free will all by themselves. Still, it does appear that a close look at the empirical data can afford us a certain kind of insight. The results help us to get at the roots of our sense that there is a puzzle here and, thereby, to open up new avenues of inquiry that might not otherwise have been possible.
Joshua Knobe is an experimental philosopher affiliated both with the Program in Cognitive Science and the Department of Philosophy at Yale University. He is editor with Shaun Nichols of Experimental Philosophy. Watch a video introduction featuring the comedian Eugene Mirman here.