Free Will and the Philosophy of Science

Neuroscience and Neurology CategoryFor many years the discussion over the existence of free will was limited to philosophers and theologians. Scientists started talking about free will once science started separating as a discipline from philosophy. However, it wasn’t until the rise of functional neuroimaging that some neuroscientists started studying if the brain and deterministic brain processes could explain away free will. In short, some scientists want to discover whether or not free will is merely an illusion, an idea humans create out of an innate desire to feel in control.

IllusionIn a 2008 article in Nature Neuroscience, researchers believe that their findings indicate that free will is at best highly implausible. They stated they were able to accurately predict, using fMRI and statistical modeling, people’s responses up to 10 seconds before a response was made on a simple task where participants were asked to push a button with their left or right hand. Activity in the prefrontal and parietal cortices preceded response by up to 10 seconds. The researchers interpret their results as showing there is no evidence for free will. Because this brain activity occurs before people are aware of their response, the authors feel that free will is nothing more than an illusion. The mechanics of the brain determine our responses.

On the other hand, assuming the findings are valid and replicable, there are other interpretations. I’ll explain an alternative interpretation by explaining a little epistemology and the philosophy of science first. Modern science is founded on the philosophical assumptions of materialism, naturalism, and empiricism — among other ideas. Materialism assumes determinism. Determinism is mechanistic and denies free will.

Because determinism is assumed, it is not possible to really study free will using neuroscience methods because it’s saying and doing the following:

  • Believe that free will may or may not exist.
  • Use methods (e.g., scientific method) that assume that free will doesn’t exist.
  • Conduct free will research that apparently shows free will does not exist.
  • Interpret the results as showing that free will does not exist.

One fault with this research is that the authors assume determinism and mechanism of our material world and then they try to study something that does not exist according to the foundational assumptions of modern science. It is thus not surprising that they view their research findings as pointing towards the nonexistence of free will.

Why is it important to understand the philosophical assumptions that underline modern science, including neuroscience and psychology? In psychology, the question of free will is important because it can change how a psychologist views abnormal behavior (and even normal behavior). It can change how psychotherapy is conducted (e.g., personal responsibility versus repressed early experiences). If a psychologist takes a deterministic approach to science or therapy, her approach can be very different than someone who takes a non-deterministic (e.g., free will) approach.

In closing I’d like to throw out a couple questions for the readers. Is there room for assuming free will in neuroscience research? Are there other ways of approaching the question of free will, especially as it relates to science research?


Soon, C., Brass, M., Heinze, H., & Haynes, J. (2008). Unconscious determinants of free decisions in the human brain Nature Neuroscience, 11 (5), 543-545 DOI: 10.1038/nn.2112

Jared Tanner, PhD

Jared Tanner has a Ph.D. in clinical psychology with an emphasis in neuropsychology. His interests are mainly neuroimaging and neuroanatomy. He spends his research time looking at the structure of gray and white matter in the brains of people with Alzheimer's disease and Parkinson's disease. With a focus on neuropsychology, he is also interested in how normal and abnormal brain structure relates to cognitive and behavioral functioning.
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