Martin Heisenberg on Free Will

This  week’s Nature magazine (14 May 2009) has an essay on free will by Martin Heisenberg (son of Werner), chair of the University of Wurzburg’s genetics and neurobiology section of their BioCenter.

Since the indeterminacy principle was his father’s work, the comment that the physical universe is no longer determined and that nature is inherently unpredictable comes as no surprise.

What is unusual is that Heisenberg finds evidence of free behavior in animals, including some very simple ones such as Drosophila, on which he is a world expert.

He says:

"the activation of behavioural modules is based on the interplay between chance and lawfulness in the brain. Insufficiently equipped, insufficiently informed and short of time, animals have to find a module that is adaptive. Their brains, in a kind of random walk, continuously preactivate, discard and reconfigure their options, and evaluate their possible short-term and long-term consequences.

"The physiology of how this happens has been little investigated. But there is plenty of evidence that an animal’s behaviour cannot be reduced to responses. For example, my lab has demonstrated that fruit flies, in situations they have never encountered, can modify their expectations about the consequences of their actions. They can solve problems that no individual fly in the evolutionary history of the species has solved before. Our experiments show that they actively initiate behaviour."

When you combine some randomness with some "lawful" (read evolved and adequately determined) behaviors you get something like free will.

This is more or less exactly my work of the last few decades. Free will is a two-stage process.

First there is a random generation of alternative possibilities, some of which may be truly creative in the sense that they are new information in the universe.

Then an adequately determined will selects, from among these possibilities, the one best suited to one’s character and values, along with one’s current desires.

First free, then will.

It is not that the will is free in the sense of random. The will is determining and adequately determined.

Several other philosophers and scientists have had something close to this idea since William James in 1884, including Henri Poincaré, Arthur Holly Compton, A.O. Gomes, Karl Popper, Henry Margenau, Daniel Dennett, Robert Kane, and Alfred Mele.

For more details, you might want to look at a few of the web pages on informationphilosopher.com.

There you will find web pages on the above thinkers and over one hundred others who have considered the problem of free will, including several gardeners.

I am working on a history of the free will problem here (a very long page).
http://www.informationphilosopher.com/freedom/history/

Here is my version of the two-stage model (a much shorter page).
http://www.informationphilosopher.com/freedom/cogito/

Compare the standard  argument against free will, which separately attacks randomness and strict determinism.  Taken together, randomness and adequate determinism suggest that many compatibilists might consider a merely adequate compatibilism?
http://www.informationphilosopher.com/freedom/standard_argument.html

Comments

[Bob Doyle]

Nature has posted the Heisenberg article online, as part of the current issue for a short time, perhaps.

http://www.nature.com/nature/journal/v459/n7244/pdf/459164a.pdf

[Jeff Orchard]

I think that bringing something like quantum physics is unnecessary. A large neural network has so many states that the idea of EXACTLY repeating any behaviour is astronomically small. I looked at your blog briefly... just enough to see that you refer to thermal and quantum noise. I appreciate the inclusion of thermal noise, and expect that's enough.

[Bob Doyle]

Hi all,

My letter to the editor of Nature responding to Heisenberg's essay was just published in this week's issue of Nature.
http://www.nature.com/nature/journal/v459/n7250/pdf/4591052c.pdf

Here is what it said:

Free will: it’s a normal
biological property,
not a gift or a mystery

SIR — In his Essay 'Is free will an
illusion?' (Nature 459, 164–165;
2009), Martin Heisenberg argues
that humans must have free
will because freedom of action
has been demonstrated in other
animals — including those as
small as fruitflies and bacteria.
Heisenberg’s case rests on a
combination of random chance
and lawfulness, escaping the
classic two-horned dilemma
of determinism versus
indeterminism that is so popular
in introductory philosophy
courses and textbooks.

Starting with William James
in 1884, such a two-stage
combination of ‘free’ and
then ‘will’ has frequently been
proposed by philosophers and
scientists: notable among these
are some quantum physicists
after Martin’s father, Werner
Heisenberg, established
irreducible physical randomness
with his indeterminacy principle in
1927. But academic philosophers,
particularly those who work in
the Anglo-American school of
analytical language philosophy,
have been reluctant to embrace
these ideas.

The philosophers’ standard
argument against free will is
simple and logical. If our actions
are determined, we are not free.
If nature is not determined,
then indeterminism is true.
Indeterminism implies that our
actions are random. If our actions
are random, we did not will them.

Heisenberg’s proposal makes
freedom a normal biological
property of most living things
and not a metaphysical mystery
or a gift from God to humanity.
Its genius is that it combines
randomness with an adequate
macroscopic determinism
consistent with microscopic
quantum mechanics.

John Locke wrote in his Essay
Concerning Human Understanding,
Book II, that it is not the will
that is free but the man. The
will determines our actions.
Heisenberg writes that Kant
would have been pleased. Locke
too might have been pleased to
see this return to common sense.
We may not have metaphysical
free will but we do have
biophysical free will.

Robert O. Doyle Astronomy
Department, Harvard University,
77 Huron Avenue, Cambridge,
Massachusetts 02138, USA