The free will problem
In the first year of my medical education at the University of Münster in northwestern Germany, our professor of zoology Bernhard Rensch (1900-1990), the author of [1] who was a chimpanzee researcher, told us in 1960 that "we humans lack free will. Our thought and will are neurophysiological processes in the brain that completely determine our behavior. We are not so different from the apes".
As an 18-year-old student I was frightened and depressed to hear this dreadful news. It took 20 years of inquiry, including brain research and philosophical studies, until I was able to recognize in 1980 that all natural-scientific, psychological and sociological talk about the unfreedom of the will is nothing more than pure nonsense. The free will problem is a philosophical-ethical problem and cannot be resolved by zoology and chimpanzee research, neurophysiology, physics, chemistry, psychology, sociology, and related sciences for the following reason: Morality and moral responsibilty in a community (group, family, society) presuppose that human beings be autonomous agents. Autonomy means having free will to make decisions free from any kinds of constraints.
However, the possibility and existence of free will have long been controversely debated in philosophy, religion, and sciences. On the one hand, there are those, called metaphysical determinists, who maintain that there is no free will; human decision-making is completely determined by biological and social constraints. Metaphysical libetrarians, on the other, maintain that the opposite is true. Metaphysical determinism is currently the mainstream view. Neuroscientists and a group of philosophers of mind have established the so-called neurophilosophy according to which there is no free will.
The U.S.-American neurophysiologist Benjamin Libet and his collaborators conducted a series of experiments in the 1980s to analyze the relationships between the activity of cerebral neurons and voluntary acts. Among other things, they found that "Freely voluntary acts are preceded by a specific electrical charge in the brain (the 'readiness potential', RP) that begins 550 milliseconds before the motor act. Human subjects become aware of intention to act 350–400 ms after RP starts, but 200 ms before the motor act". These authors didn't conclude from their finding that there was no free will. But they triggered the emergence of the neuroscience-based unfree will doctrine in neurophilosophy which says that the subjective feeling of free choice is an illusion; there is no free will; decisions and actions are caused by natural laws operative in the brain.
No neurophysiological counter experiments are required to show, however, that at least some human beings do in fact have free will. This is easily demonstrated by the self-defeat of the unfree will doctrine above in the following way:
The unfree will doctrine as applied to its proponent: According to the neurophysiological theory of the unfreedom of our will, I, "an advocate of the unfree will doctrine", have no free will. All my decisions are caused by natural laws operative in my brain neurons. Thus, I am unable to make deliberate decisions and to freely choose between the decision to do a particular action and the decision to omit doing it. Obviously incapable of being a self-reflective agent, I am a mere automaton that must obey the biochemical dictates of my brain neurons. This brings with it that it is not my own will to tell you what I am telling you right now. I am determined to do so by natural laws operating in my brain. What you are hearing or reading right now is in fact those laws speaking to you. Needless to say, therefore, that also the theory of the unfreedom of the will is their theory, not mine, so that I am not responsible for advancing their theory. Nor can I make any claim regarding its truth or untruth. Any epistemological question regarding their theory must be directed to the natural laws themselves residing in my brain. If I were to make a truth claim regarding their theory, this decision and claim would also be determined by those natural laws. So, it would in fact be the natural laws themsleves saying that they tell the truth. Even my very pronouncement that everything I want and do is determined, is determined. To properly understand my awkward and pitiful situation, you are allowed to presume that I am speaking pure nonsense. For I am a distinguished professor dr. dr. h.c. mult. of neurophilosophy and am paid by the state for propagating sophisticated nonsense of the higher order made by natural laws in my brain neurons.
To prevent such obvious nonsense, we must abandon the unfree will doctrine to suppose that free will indeed exists, that is, there is at least one human being who at least sometimes is capable of making decisions free from any constraints. For this theory of free will, see ([2], pp. 156-162).
[1] Rensch B. Homo Sapiens: From Man to Demigod. New York: Columbia University Press, 1972. (The original, German subtitle reads "From Animal to Demigod": Homo sapiens. Vom Tier zum Halbgott. Vandenhoeck & Ruprecht, Göttingen, 1970.)
[2] Sadegh-Zadeh K. Handbook of Analytic Philosophy of Medicine. Dordrecht: Springer, 2015.