When the topic of free will appears in Nature, it is normally being tossed unceremoniously in the rubbish bin. There is a lot of recent research which supports this. Last year, for instance, researchers at the Max Planck Institute used brain scanners to show that brains decide 7 seconds before people are aware of making a choice. "By the time consciousness kicks in, most of the work has already been done," said the lead author. Much of the latest research in science journals “demonstrates” that human behaviour is never self-generated and that freedom is an illusion. This is, of course, is a matter of no little consequence for bioethics.

So there’s good news and bad news about free will in this week’s Nature. The good news is that a Nature author is contending that it exists. Martin Heisenberg, of the University of Würzburg, in Germany, writes: “self-initiated action is not in conflict with physics and can be demonstrated in animals. So, humans can be considered free in their behaviour, in as much as their behaviour is self-initiated and adaptive.” He believes that the key to solving this ancient conundrum is quantum physics and behavioural biology.

And that’s the bad news. Dr Heisenberg proves that humankind has free will by showing that Escherichia coli does, too. An expert on fruit flies, he sees that “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.”

The fly in the ointment, so to speak, is the philosopher Immanuel Kant. Heisenberg uses Kant’s definition as the benchmark for freedom: “a person acts freely if he does of his own accord what must be done”. If a fruit fly is free, surely we are, too.

Hmmm. The philosopher Jean-Paul Sartre wrote famously that "man is condemned to be free". It’s unlikely that he thought that E. coli was rattling the same chains. Perhaps Professor Heisenberg’s “freedom” isn’t the same one that enraptured the existentialists. So perhaps the inclusion of this essay in Nature isn't so surprising after all. ~ Nature, May 13