INTERVISTA. Il fisico e filosofico Robert Doyle difende, proprio attraverso la scienza,
quel libero arbitrio negato da molti studiosi

Placido pomeriggio sul divano. Alzarsi per andare al frigorifero e prendere una bibita o restare comodamente seduti? Non una grande decisione, eppure ci si può riflettere qualche secondo, poi scegliere e infine alzarsi.

Niente di strano, nulla da spiegare per la maggior parte di noi. Non useremmo i termini tecnici di “libero arbitrio” e “causazione mentale”, ma ciò cui ci riferiamo è proprio l’idea che davanti a noi abbiamo corsi di azione alternativi tra cui optare senza costrizioni (restare seduti o alzarsi) e che la nostra “mente” comanda il corpo in modo diretto. Ma le cose non sono affatto così semplici. Semplificando molto, se ogni cosa ha una causa fisica (come la scienza sembra dirci) che segue le leggi immutabili della natura, non siamo liberi, ma determinati, e non ci sono cause mentali, ma solo il cervello che agisce.

«È lo scandalo della filosofia», dice Robert Doyle, astronomo e creatore di tecnologia, docente alla Harvard University, convertito con zelo militante e inesausto alla causa del libero arbitrio. Così ha intitolato anche un suo recente, denso volume (disponibile liberamente su Internet nel ricchissimo sito www.informationphilosopher.com). Come mettere fine allo scandalo costituito dal negare la libertà degli esseri umani e la realtà della mente, dovuto all’affermarsi del riduzionismo materialistico? Doyle, 76 anni, in questi giorni a Milano, ha un’idea precisa, legata alla meccanica quantistica. «La domanda centrale del classico problema mente-corpo è come una mente immateriale possa muovere un corpo materiale se le catene causali sono limitate all’interazione tra oggetti fisici», spiega. «In sintesi, il mio modello prevede una mente immateriale come pura informazione all’interno del sistema fisico che elabora quell’informazione, ovvero il cervello. In questo modo, si arriva a un fisicalismo non riduttivo e un dualismo emergentistico». Il punto sta nella maniera in cui è concepita l’informazione (che, tra l’altro, è proprio quella cosa che sta nei messaggi che ci scambiamo e nei libri che leggiamo).

«L’informazione – dice Doyle – è fisica ma immateriale. Non è né materia né energia, anche se ha bisogno di entrambe per la sua manifestazione. L’indeterminismo della fisica quantistica “rompe” la catene causali usate per ridurre i fenomeni biologici alla fisica e alla chimica e gli eventi mentali agli eventi neuronali. Ma ciò non vuole dire che le nostre scelte siano casuali». Il quadro qui si complica. Una delle difficoltà del libero arbitrio discende dal fatto che è incompatibile con il determinismo (tutto è già scritto), ma anche con l’indeterminismo (se non ci sono leggi costanti, le nostre azioni e i loro risultati saranno casuali, e libertà non è tirare ogni volta la monetina). La meccanica quantistica dice in sintesi che il comportamento delle particelle subatomiche si descrive secondo probabilità e non certezze, anche se poi le previsioni permesse dalla teoria sono accuratissime. Doyle (con altri studiosi) propone allora di spiegare come l’intuizione della nostra libertà sia supportata da un modello “a due stadi”.

«Il modello Cogito – riassume il fisico-filosofo – implica che molti eventi casuali a livello quantistico creino genuine possibilità alternative nel cervello. La mente informazionale, registratore e riproduttore di esperienze, grazie alla volontà può dare il suo assenso a una di esse, con una scelta adeguatamente determinata (cioè non casuale), facendo in modo che la possibilità di un futuro aperto si trasformi in un passato chiuso e inalterabile». Ciò ha a che fare con il collasso della funzione d’onda, uno dei concetti chiave della fisica quantistica. Una soluzione al mistero della libertà (e della causazione mentale) che non convince tutti gli studiosi, ma ha il pregio di fornire una spiegazione scientifica a un’intuizione fortissima del senso comune e di resistere al materialismo riduzionistico. Doyle trova spazio anche per una lettura morale: «Esiste un Bene oggettivo? Secondo me sì: ha la forma della conservazione delle strutture di informazione (quelle che danno vita all’uomo) contro l’entropia, che è l’incarnazione del diavolo».

IL CONVEGNO

DAL LABORATORIO ALLA METAFISICA. E RITORNO

Si apre oggi pomeriggio all'Università Cattolica (via Nirone, 15) il convegno 'La fisica quantistica incontra la filosofìa della mente ' (Programma). Chiamati a raccolta per tre giorni da Antonella Corradini e da Uwe Meixner dell'Università di Augusta, si confrontano i maggiori esperti (Kane, Stapp, Hameroff, Doyle) dell'applicazione della scienza ai dilemmi legati all'essere umano, alla sua costituzione e alla sua libertà.

Andrea Lavazza

Doyle: "Mind and freedom? Hidden in quanta »

A placid afternoon on the couch. Should you get up to go to the fridge and grab a drink or stay sitting comfortably? Not a big decision, but you can meditate for a few seconds, then choose and then get up. Nothing strange, nothing to explain to most of us. We would not use the technical terms of "free will" and "mental causation", but what we are referring to is precisely the idea that we have before us alternative courses of action including without any constraints the options (sit or stand up) and that our "mind" controls the body directly. But things are not so simple. In very simple terms, if everything has a physical cause (such as science seems to be saying), it follows from the immutable laws of nature that we are not free, but determined, and that there are no mental causes, but only the brain that acts.

"It is the scandal in philosophy," says Robert Doyle, astronomer and creator of technology, a professor at Harvard University, converted with zeal and tireless activist for the cause of free will. So he titled his recent, dense volume (available freely on the Internet in the rich website www.informationphilosopher.com). How to put an end to the scandal of denying the freedom of human beings and the reality of the mind, due to the emergence of materialistic reductionism? Doyle, 76, these days in Milan, has a clear idea, related to quantum mechanics. "The central question of the classic mind-body problem is how an immaterial mind can move a material body if causal chains are limited to the interaction between physical objects," he explains. 'In short, my model predicts a immaterial mind as pure information within the physical system that processes that information, or the brain. In this way, we arrive at a non-reductive physicalism and emergent dualism. " The point lies in the manner in which the information is intended (which, by the way, is the very thing that is in the messages that we exchange and in the books we read).

"The information - says Doyle - is physical but immaterial. It is neither matter nor energy, even if it needs both for its manifestation. The indeterminism of quantum physics "breaks" the causal chains used to reduce biological phenomena in physics and chemistry and mental events to neural events. But that does not mean that our choices are random. " The picture here is complicated. One of the problems stems from the fact that free will is incompatible with determinism (everything is already written), but also with indeterminism (if there are consistent laws, our actions and their results will be random, and freedom is not pulling the coin each time). Quantum mechanics says in summary that the behavior of subatomic particles is described according to probabilities and not certainties, even if the weather permitted by the theory are very accurate. Doyle (with other scholars) proposes then to explain how the intuition of our freedom model is supported by a "two-stage" model.

"The Cogito model - summarizes the physicist-philosopher - includes a lot of random events at the quantum level that create genuine alternative possibilities in the brain. The informational mind (an experience recorder and reproducer) can give its assent to to one of these, with its choice adequately determined (ie non-random), making sure that the possibility of an open future turns into a past closed and unalterable. " This has to do with the collapse of the wave function, one of the key concepts of quantum physics. A solution to the mystery of freedom (and of mental causation) that does not convince all scholars, but has the advantage of providing a scientific explanation for the strong intuition and common sense to resist the reductionist materialism.

Doyle also has space for a moral reading: "There is a good, objective? I think so: it has the form of the conservation of information structures (those that give life to man) against entropy, which is the incarnation of the devil.

Do We Have Free Will?

Professor Antonella Corradini of Cathoic University has convened a conference at Catholic University this week with experts from all over the world asking whether quantum physics can help us to understand the power of mind over matter, the problem that René Descartes posed nearly 400 years ago in his Principles of Philosophy, and the problem of free will that Greek thinkers like Democritus and Epicurus puzzled over at the dawn of philosophy over 2000 years ago.

How can it possibly be that with all these years to think about the problem of free will and the mind-body problem, that they are still problems taught in philosophy classes around the world? Even more astonishing, why do so many modern scientists think that the problems will be solved some day by finding underlying causes that will explain our every action!

Neuroscientists, probing our brains with magnetic resonance imaging, are sure they are about to see how our neurons are in charge of our actions. Cognitive scientists, who think that our brains are simply computers, think they will soon discover the programming that shows we are all simply warm-blooded robots.

When most people of common sense think that we are deciding what to do, and are willing to take responsibility for our actions, except when we are obviously limited by powers beyond our control, whether external force or internal compulsions, how can our schools be teaching impressionable young minds that they are biological machines whose every action is completely determined?

In a recent survey, sixty percent of philosophers think that our free will is compatible with being determined, as long as we are one of the links in the causal chain determined by the laws of nature. Ten percent say there is no free will at all. Only thirteen percent think we have free will, and two-thirds of those have strong religious leanings, typically Catholics who are taught that free will is a gift of God.

This brings us back to the deep reasons for the original problems and why they are still with us. Democritus invented the idea of deterministic laws of nature around 400 B.C.E. to deny that the whims of arbitrary gods were manipulating our fates. Everything, including ourselves, is made of tiny atoms following universal laws of motion. And stop worrying about the gods, he said, they are too busy to be interfering in our lives.

About a hundred years later, his fellow atomist and materialist, Epicurus, was appalled that our actions might be completely determined. “It’s better to follow the myth about the gods than to be slaves to the ‘fate’ of the physicists,” he said. “We can pray to the gods for forgiveness, but physics gives us no freedom.” Epicurus, and his interpreter, the great Roman poet, Lucretius, pointed to the way out. A tiny “swerve” (clinamen, declinando) of the atoms in our minds, at no fixed time or place (nec tempore certo nec regione loci certa) “breaks the bonds of fate” (fati foedera rumpat) and we can go wherever our minds take us (sed ubi ipsa tulit mens).

With two thousand years of progress behind him, Descartes thought he had found a similar answer, a special freedom could be found in an “undetermined mind.” Although our minds are finite, compared to the infinite mind of God, so we cannot expect to understand it, he said, it would be absurd to deny our free will just because we cannot comprehend it. And then he proclaimed two things, “Freedom of the will is self-evident,” and “It is also certain that everything was pre-ordained by God.”

If we substitute for belief in God the scientists’ belief that they are discovering the laws of nature, you see the current dilemma.

Can quantum physics show us the way out? When Albert Einstein in 1916 finished his work on relativity, he found that quantum particles appeared spontaneously, at no particular time, going in no particular direction. Here was Epicurus “swerve” exactly. But Einstein simply could not believe it. God does not play dice,” he said.

Our most practical and plausible solution to the problem of free will is that quantum events in our brains are the origins of freely generated creative new ideas that neither laws nor gods could have pre-determined or pre-ordained. In a second step, we then evaluate these “random” ideas that “pop into our heads,” in the light of our motives, reasons, desires, and we select the best one in an “adequately determined” way. Our actions are caused, but some of the causes originate in our own minds, as Epicurus and Descartes thought. Our minds can therefore control our bodies, as Corradini’s conference participants hope to show, despite the claims of most philosophers and scientists.

According to the new “information philosophy” of Harvard philosopher and scientist Bob Doyle, our minds are simply the abstract information processing in our brains. This solves the “mind-body problem.” Information is neither matter nor energy, though it needs matter for its embodiment and energy for communication. Information is immaterial, the software in the brain hardware, the “ghost in the machine,” the modern spirit or soul.

Our immaterial minds exercise our free will in two stages, first the free generation of new thoughts, followed by the willed selection of the best action. We solve the problem of “free will” by breaking it into two parts - first “free,” then “will.”

Bob Doyle
Information Philosopher
Astronomy Department
Harvard University

For Avvenire
2 June 2013