thomas_metzinger's picture
Professor of Theoretical Philosophy, Johannes Gutenberg-Universität Mainz; Adjunct Fellow, Frankfurt Institute for Advanced Study; Author, The Ego Tunnel
The Forbidden Fruit Intuition

We all would like to believe that, ultimately, intellectual honesty is not only an expression of, but also good for your mental health. My dangerous question is if one can be intellectually honest about the issue of free will and preserve one's mental health at the same time. Behind this question lies what I call the "Forbidden Fruit Intuition": Is there a set of questions which are dangerous not on grounds of ideology or political correctness, but because the most obvious answers to them could ultimately make our conscious self-models disintegrate? Can one really believe in determinism without going insane?

For middle-sized objects at 37° like the human brain and the human body, determinism is obviously true. The next state of the physical universe is always determined by the previous state. And given a certain brain-state plus an environment you could never have acted otherwise — a surprisingly large majority of experts in the free-will debate today accept this obvious fact. Although your future is open, this probably also means that for every single future thought you will have and for every single decision you will make, it is true that it was determined by your previous brain state.

As a scientifically well-informed person you believe in this theory, you endorse it. As an open-minded person you find that you are also interested in modern philosophy of mind, and you might hear a story much like the following one. Yes, you are a physically determined system. But this is not a big problem, because, under certain conditions, we may still continue to say that you are "free": all that matters is that your actions are caused by the right kinds of brain processes and that they originate in you. A physically determined system can well be sensitive to reasons and to rational arguments, to moral considerations, to questions of value and ethics, as long as all of this is appropriately wired into its brain. You can be rational, and you can be moral, as long as your brain is physically determined in the right way. You like this basic idea: physical determinism is compatible with being a free agent. You endorse a materialist philosophy of freedom as well. An intellectually honest person open to empirical data, you simply believe that something along these lines must be true.

Now you try to feel that it is true. You try to consciously experience the fact that at any given moment of your life, you could not have acted otherwise. You try to experience the fact that even your thoughts, however rational and moral, are predetermined — by something unconscious, by something you can not see. And in doing so, you start fooling around with the conscious self-model Mother Nature evolved for you with so much care and precision over millions of years: You are scratching at the user-surface of your own brain, tweaking the mouse-pointer, introspectively trying to penetrate into the operating system, attempting to make the invisible visible. You are challenging the integrity of your phenomenal self by trying to integrate your new beliefs, the neuroscientific image of man, with your most intimate, inner way of experiencing yourself. How does it feel?

I think that the irritation and deep sense of resentment surrounding public debates on the freedom of the will actually has nothing much to do with the actual options on the table. It has to do with the — perfectly sensible — intuition that our presently obvious answer will not only be emotionally disturbing, but ultimately impossible to integrate into our conscious self-models.

Or our societies: The robust conscious experience of free will also is a social institution, because the attribution of accountability, responsibility, etc. are the decisive building blocks for modern, open societies. And the currently obvious answer might be interpreted by many as having clearly anti-democratic implications: Making a complex society work implies controlling the behavior of millions of people; if individual human beings can control their own behavior to a much lesser degree than we have thought in the past, if bottom-up doesn't work, then it becomes tempting to control it top-down, by the state. And this is the second way in which enlightenment could devour its own children. Yes, free will truly is a dangerous question, but for different reasons than most people think.