Lately, there seems to a high level of certainty among scientists that determinism is the only rational and scientific position one can take in regard to the question of free will. Any defense of free will or volition is seen as anti-scientific in ways similar to the way behaviorists of the first half of the twentieth century thought about subjective experience. The behaviorists, in recognizing that subjective experience could not be easily quantified, concluded that it therefore didn’t exist, and that human behavior could be fully explained in terms of stimulus-response. Similarly, the determinists, in recognizing that free will cannot be easily quantified or explained, have concluded that it doesn’t exist and can be fully explained by the stimulus-response of physical causation.

Determinists claim that free will is an illusion, that our thoughts and actions are determined by the electrochemical activity in our brains. They ask: If all physical phenomena can be reduced to physical cause-and-effect relationships, then why would our brains and minds be exempt? Everything from the motions of the planets to the circulation of our blood can be explained in terms of physics, chemistry, and biology; and the brain, as part of our body, cannot be exempt from those laws. Further, since, to the best of our knowledge, our minds arise out of brain activity, it holds that our minds should be subject to those same physical, deterministic laws.

To the determinist, I have no choice but to be typing this and you have no choice regarding how you will respond. Determined by the anatomy, physiology, and biochemistry of our brains, our actions are fully determined and the perception of choice is therefore an illusion. The same holds for everyone; just as my thoughts and actions are determined, the thoughts and actions of others are similarly determined. If you accept the full implications of this (which I think few people do), you realize that this runs counter to the assumption of choice and responsibility that underlies all academic and moral debate, as well as all psychological therapy and counseling. It also contradicts every waking moment of our everyday experience.

But the fact that it contradicts our assumptions and experience doesn’t necessarily make it untrue. The larger problem with determinism is the structure of the argument and the certainty to which its proponents hold it as the only reasonable conception of truth regarding free will.

The fact is, science has no satisfactory explanation for how consciousness and subjective experience arises out of the brain. Within the scientific and philosophical community, consciousness is an open question, a mystery that few people pretend to have solved. The subject of free will is inextricably tied to the subject of consciousness, so if we haven’t solved consciousness, it goes without saying that we haven’t solved the problem of free will. It’s an open question as long as consciousness is an open question, and the problem of consciousness is well established.

Science, for example, can tell us with great precision about the wavelengths of light that produce the color red. Science can also describe the electrochemical propagation of impulses from the retina through the optic nerve to the visual cortex of the brain that the color red produces. MRI imaging can also highlight which parts of the brain are activated in response to the specific object and color. But despite all of this, there is, as of yet, no explanation as to what it means to perceive the color red. We still have no idea how all of the electrical and chemical activity in the brain and all of the neuronal firing actually creates consciousness. Further, if we can’t explain consciousness, then we certainly can’t explain something like free will which depends on our understanding of consciousness and the mind-brain interaction.

This is where the appeal to ignorance becomes relevant. The appeal to ignorance is “the assumption of a conclusion or fact based primarily on lack of evidence to the contrary.” The argument can take the following forms:

X is true because you cannot prove that X is false.
X is false because you cannot prove that X is true.

Determinism is claiming that free will is false because you cannot prove that is is true, or alternatively, that the mind is physically determined because you cannot prove that it isn’t.

You cannot use your lack of understanding regarding a subject as a premise for your conclusion. The determinist is essentially making this argument:

- Science can only explain things in terms of physical cause and effect.
- Science has no explanation for how consciousness and subjective experience arises out of the brain.
- Therefore, consciousness can be reduced to physical cause and effect.

The fallacy is obvious; our lack of understanding of consciousness cannot be taken as a premise for our claim that we understand it to be entirely physically determined. It’s possible that our brains and minds are synonymous and physically determined, but without a conclusive explanation of consciousness we cannot make this claim with any degree of certainty or confidence.

Until there is conclusive evidence to the contrary, I have no reason to doubt my own capacity for free choice, which is continuously confirmed as part of, in fact the essence of, my subjective experience. I am justified in believing this in exactly the same way I’m justified in believing that the external world and other minds exist. If I want to take skepticism to the extreme, I could doubt all of this, but it would run counter to most of my experience and evidence and would be of no practical value whatsoever.