The more we understand about how the world works the more fraught the questions of our place in the causal network of the world may seem. In particular, the progress made in understanding how the mechanisms of our brain influence the outward behavior of our minds consistently raises questions about how we should interpret the control we have over our behavior. If we can understand the neurological processes in a causal network that explain the way we act, in what sense can we preserve an understanding of our behavior as ‘up to us’?

This has been a concern for those of us with mental illness and neurological disorders for some time: having scientific accounts of depression, anxiety, mania, and dementia can help target treatment and provide us with tools to navigate relationships with people that don’t always behave like ‘themselves’. In serious cases, it can inform how we engage with people who have violated the law: there is a rising trend to use “behavioral genetics and other neuroscience research, including the analysis of tumors and chemical imbalances, to explain why criminals break the law.”

In a current case, Anthony Blas Yepez is using his diagnosis with a rare genetic abnormality linked to sudden violent outbursts to explain his beating an elderly man to death in Santa Fe, New Mexico, six years ago in a fit of rage. His condition explains how he wasn’t “fully in control of himself when he committed the crime.”

Putting aside our increasing ability to explain the psychological underpinnings of our behavior more causally or scientifically, our criminal justice system has always acknowledged a distinction between violent crimes committed in states of heightened emotionality and those performed out of more reasoned judgments, finding the latter to be more egregious. If someone assaults another immediately after finding out they cheated with a significant other, the legal system punishes this behavior less stringently than if the assault takes place after a “cooling off period”. This may be reflective of a kind of acknowledgement that our behavior does sometimes “speak” less for us, or is sometimes less in our control. Yepez’s case is one of a more systematic sort where he is subject to more dramatic emotionality than the standard distinction draws.

Psychological appeals for lesser sentences like Yepez’s are successful in about 20% of cases. Our legal system still hasn’t quite worked out how to interpret scientific-causal influences on behaviors, when they are not complete explanations. Having a condition like Yepez’s, or other psychological conditions we are gaining more understandings of every year, still manifest in complex ways in interaction with environmental conditions that make the explanations fall short of having a claim to fully determining behavior.

It does seem that there is something relevantly different in these cases; the causal explanations appear distinct. As courts attempt to determine the implications of that difference, we can consider the effect of determination-factors in how we understand behavior.

John Locke highlights the interplay between what we may identify as the working of our will and more external factors with a now-famous thought experiment. Imagine a person in a locked room. There seems to be an intuitive difference between such a person who wishes to leave the room but cannot – their will is constrained and they cannot act freely in this respect. On the other hand, something seems importantly different if the person were in the locked room and didn’t know the door was locked – say they were in rapt conversation with a fascinating partner and had no desire to leave. The world may be “set up” so that this state of affairs is the only one the person could be in at that moment, but it isn’t clear that their will is not free; the constraints seem less relevant.

We can frame the question of the significance of the determination of our wills in another way. While not all of our actions are a result of conscious deliberation, consider those that are. When you question what to eat for lunch, what route to take to get to your destination, which option to take at the mechanics, etc., what would result from your certainty that your ultimate decision is determined by the causal network of the world? If, from the perspective of making a decision, we consider ourselves not to be a source of our own behavior, we would fail to act. We would be rendered observers to our own behavior, yet in a perspective of wondering what to do.

Note an interesting tension here, however: after we decide what to do (to have a taco, take the scenic route, replace the transmission) and perform the relevant action, we can look back at our deliberative behavior and wonder at the influences that factored into the performance. It often feels like we are in control of our behavior at the time – say, when we consider tacos versus hamburgers and remember how delicious, fresh and cheap the fish tacos are at a stand nearby, it seems that these factors lead to seeking out the tacos in a paradigmatic instance of choice.

But what if you had seen a commercial for tacos that day? Or someone had mentioned a delicious fish meal recently? Or how bad burgers are for your health or the environment? What if you were raised eating fish tacos and they have a strong nostalgic pull? What if you have some sort of chemical in your brain or digestive system that predisposes you to prefer fish tacos? If any of these factors were the case, does this undermine the control you had over your behavior, the relevant freedom of your action? How do such factors relate to the case that Locke presents us with – are they more or less like deciding to stay in a locked room you didn’t know was locked?

These questions could be worrying enough when it comes to everyday actions, but they carry import when the behaviors in question significantly impact others. If there is a causal explanation underpinning even the behaviors we take to be up to our conscious deliberation, would this alter the ways we hold one another responsible? In legal cases, having a causal explanation that doesn’t apply to typical behaviors does lessen the punishment that seems appropriate. Not everyone has a condition that correlates to violent outbursts, which may make this condition a relevant external factor.