Michio Kaku is Demonstrably Wrong about Free Will
by Benjamin Studebaker
The other day, I stumbled upon a YouTube video featuring Michio Kaku, the famous theoretical physicist and public intellectual. I usually appreciate his ability to explain complex scientific concepts in ways that are comprehensible for a lay audience, but in this video (entitled “Why Quantum Physics Ends the Free Will Debate“), Kaku stepped well outside his area of expertise and delivered a breathtakingly facile argument that any person with elementary academic training in philosophy can easily and demonstrably disprove.
Here’s the Kaku video:
Here’s the structure of what Kaku said:
- Einstein (and traditional physicists more generally) believed that the universe operated in accordance with deterministic natural laws.
- If the universe operates in accordance with natural laws, and we are part of the universe, then we operate in accordance with natural laws and consequently there is no free will.
- However, quantum physics subsequently established the Heisenberg Uncertainty Principle, which establishes that there are things about the universe that are indeterminate (i.e. that cannot be known or predicted with laws), specifically we cannot know both the position and momentum of an electron simultaneously.
- Therefore determinism is false.
- Therefore free will is true.
Kaku’s mistake is in treating determinism and free will as though necessarily one or the other must be true. It is quite possible that both are false, depending on how we define the terms. For Kaku, “determinism” seems to be Einstein’s view that the universe operates mechanistically exclusively according to natural laws. Kaku doesn’t explicitly define free will–he seems to assume that free will is simply the converse of Einstein’s view. But this is not at all how philosophers define free will.
Free will does not simply require that determinism is false, it requires that people be self-determining–that the decisions they make are truly their own in some relevant sense. Uncertainty, indeterminacy, randomness–none of these concepts establish self-determination. Indeed, indeterminacy is fundamentally incompatible with self-determination. If no one can determine both where the electron is and what direction it is going, it hardly follows that individuals can self-determine this. That is an additional claim for which quantum physics has provided no evidence whatsoever. Kaku is asserting it without any grounds for doing so. All that quantum physics has done is show that when we explain human decisions, we cannot merely credit them to heredity and environment, but must also allow that randomness may affect the decision.
Now, we can go a step further and show not only that quantum physics has not established free will, but that it cannot do so, at least insofar as we take free will to require true self-determination (not all philosophers do, but this is the way ordinary people typically take it, and conceptions of freedom that do not require it are quite bizarre). Here we can employ Galen Strawson’s argument. In simplest terms, the argument goes something like this:
- When we make conscious decisions to act a certain way, we make these decisions on the basis of reasons, and we find these reasons persuasive because of the way we are (our values, beliefs, desires, principles, physical capacities, etc.).
- So if one is to make decisions in a self-determined way, one must also self-determine the way one is.
- But to self-determine the way one is, one must have made conscious decisions to be a certain way, and made those decisions on the basis of reasons, and found those reasons persuasive because of the way one is.
- So for self-determination to be possible, one would need to be able to self-determine the process by which one self-determines, which would require that one self-determine the process by which one self-determines the process by which one self-determines. This produces an infinite regress.
- Therefore self-determination is logically impossible.
- Therefore, insofar as free will requires self-determination, free will is impossible.
As far as free will goes, it doesn’t matter whether we are the way we are because of natural laws, heredity, environment, randomness, or some combination of these things, what matters is that we cannot be the way we are because we self-determined it, and because we make our decisions based on the way we are, we cannot make our decisions on the basis of self-determination.
This is a pretty straightforward idea, and it’s been around for a while. Strawson first published his opus on this subject in the 1980’s. Bertrand Russell put the point rather simply decades earlier:
We can act as we please, but we cannot please as we please.
You can find the same thought echoed by John Locke centuries ago:
For to ask whether a man be at liberty to will either motion or rest, speaking or silence, which he pleases, is to ask whether a man can will what he wills, or be pleased with what he is pleased with? A question which, I think, needs no answer: and they who can make a question of it must suppose one will to determine the acts of another, and another to determine that, and so on in infinitum.
So it’s not like I just made this up. If Kaku had read any of the philosophical literature concerning the free will question, he would have realized that quantum physics has not and cannot prove free will, certainly not any of the conceptions of free will that Newtonian determinism would reject. The problem is that Kaku, like many scientists nowadays, seems to operate under the assumption that it is not necessary to read or study philosophy. In so doing they are making a serious mistake, because the scientific method is about empirically establishing evidence for or against specific descriptive phenomena. This is excellent, but it has limitations when we are trying to verify claims concerning nebulous abstract human concepts that are subject to a variety of diverse definitions and understandings. Before scientists can claim they can tell us whether or not free will is true, they need to settle on a persuasive and philosophically defensible understanding what we should take free will to be, whether it’s coherant, and if and how it might be proved. Scientific training is good for very many things, but it does not equip scientists with the intellectual tools to answer these questions. As a result, we can have an otherwise very intelligent expert scientist, like Kaku, make a philosophical claim that is spectacularly indefensible. The general public, which consists of people who are, for the most part, neither expert scientists nor expert philosophers, is not equipped to evaluate the claims Kaku makes, so most of those who view the video will just assume that the argumentation is correct, that someone like Kaku would not make a basic error. But that’s precisely what happened, and the public has been rendered still more ignorant than it was before.