Via Forbes : Book Of The Year: How Physics Makes Us Free
Strictly speaking, my pick for best science book of the year is actually about philosophy of science. But in this case, a philosopher has found a solution to one of the great nagging problems inspired by modern science.
If everything really is determined–right down to the subatomic particles and even lower levels, how can humans have truly free will?
Here’s what classical physics tells us about our choices, writes Jenann Ismael in her book How Physics Makes Us Free (Oxford University Press).
“It tells us that however much it seems to you that your fate hangs in the balance on those sleepless nights when you have a very difficult decision, or however spontaneous your choice of socks seemed today, everything you do is entailed by the laws of nature, given the initial conditions of the universe.”
Many scientists accept this view. But according to Ismael, who is a professor of philosophy at University of Arizona, in a sense this is only a matter of mistaking the global for the local—focusing too much on the superstructure of the laws of physics and missing the substructures of processes that are embedded within.
“My goal here,” she writes, “is entirely to look at the world through the lenses of science and break down the idea that the world as conceived by physics is inhospitable to human freedom.”
In an ironic way, it seems, the determinisms of modern physics is the inheritance of a more religious determinism.
According to Ismael, philosophers and scientists will sometimes speak in terms of a kind of origin myth to illustrate the separate elements in a physical conception of the world by saying: “First, God chose the initial conditions. Then he chose the laws. And after that, there was no more choice; everything was set in place. The rest of the history of the world is just drawing out implications of those two choices. God just sat back and let it all play out like some grand carnival ride.”
And therein lies the problem, she argues.
We pay careful attention to regularities in nature. We take the time to suss them out, and systematize the domains across which they generalize because they help us predict and control the parts of nature that we interact with. But as soon as we dignify regularities with the label “law,” there is a strong tendency to reify them and think of them as constraining the facts.
The big picture, she insists, is far more fluid.
The first part of her book lays out how the human self fits in the natural order of the deterministic universe. Here she has to tackle both the old dualism of Descartes and modern arguments that the self is fundamentally an illusion created by the neuro-physical processes in the brain.
The self is real, she argues. If it can no longer be considered an ‘object’ or substance in the metaphysical terms of Descartes, it is nevertheless, Ismael states, an emergent self-governing entity and it is the author of its thoughts and actions. Indeed, in terms of psychology and neuroscience, she writes, it’s more useful to think of the self as corporate entity than pure individual mind. But it is no less the unique source of intention and action.
If you thought, she writes, “that the self had to be a simple substance or thing— an indivisible little nugget of pure me-ness without parts or divisions— lodged in the brain, you were wrong. The sort of unity that the self possesses is a formal unity, not a material one.”
The second part of the book lays out how the actions of the self can be truly free if in fact the actions of all physical beings are determined. Ismael accepts determinism as most scientists do, and doesn’t spend any of her intellectual capital trying to attack determinism using quantum physics.
What she does is re-examine how scientists regard causality. The universe is not just a flat landscape in which one thing happens and then another in a simple succession, she writes, citing the work of UCLA’s Judea Pearl.
There are special little causal hubs built to collect influence from across the landscape and filter it through a decision process that guides behavior. These little hubs are human minds, and the control structure inside these little hubs is quite special. We look to the internal structure of these hubs to understand the emergence of selves and to understand the sense in which selves are not mere products of genetic and cultural influence, but exercise control over their own formation.
We can’t consider ourselves truly free, Ismael writes, unless we can say that we decide whether to walk across the street, move far from home, take a new job, or get married, rather than some indeterministic, one-off quantum event in our brains that knows nothing of our hearts and souls.
“And to be able to say that, we have to know what a self is. We know it has to be something between a one-off quantum event in the brain and an indivisible substance seated somewhere among the neurons and synapses.”
The solution, according to Ismael, is to recognize that deliberation brings into the chain of determination between stimulus and response not just a one-off quantum event, “but every bit of information collected over the lifetime of experience, synthesized and distilled into a subjective point of view honed over years of reflection. My decisions can draw on all of that material subsumed by my point of view and it is through the bearing of that decision on my behavior that I exercise my influence.”
In this way, she concludes, self-governance combines both self-determination and self-control. “It captures both aspects of freedom, that is, the idea that freedom involves the absence of external determination, and also the idea (only superficially in contrast) that freedom does involve a kind of inner control.”
In summary, How Physics Makes Us Free takes the offensive against the view of global laws as iron rails that keep humans from acting contrary to them.
The resulting picture of the universe is one in which there are no iron rails that keep our behaviors narrowly in check. There is only emergent regularity and complex creatures who exploit the regularity for strategic purposes. Far from being a threat to human freedom, science will appear in this picture as a systematic, holistic handmaid to effective action.
Don’t wait to add this book to your science shelves.