Daniel Dennett obituary

<span>Daniel Dennett in Stockholm, 2017. He defined his project as ‘figuring out as a philosopher how brains could be, or support, or explain, or cause, minds’.</span><span>Photograph: Shutterstock</span>
Daniel Dennett in Stockholm, 2017. He defined his project as ‘figuring out as a philosopher how brains could be, or support, or explain, or cause, minds’.Photograph: Shutterstock

Daniel Dennett, who has died aged 82, was a controversial philosopher whose writing on consciousness, artificial intelligence, cognitive science and evolutionary psychology helped shift Anglo-American philosophy from its focus on language and concepts towards a coalition with science.

His naturalistic account of consciousness, purged as far as possible of first-person agency and qualitative experience, has been popular outside academia and hotly opposed by many within it.

One of the so-called Four Horsemen of New Atheism, along with Richard Dawkins, Christopher Hitchens and Sam Harris, he also wrote on Darwinism, memes, free will and religion.

“Figuring out as a philosopher how brains could be, or support, or explain, or cause, minds” was how Dennett, aged 21, defined his project. Having gained a philosophy degree at Harvard University in 1963, he was then doing a BPhil at Oxford University under the behaviourist philosopher Gilbert Ryle, but spent most of his time in the Radcliffe science library learning about the brain.

Many philosophers were (as they still are) trying to accommodate the mind, and its subjectivity, in third-person science. Yet it seems impossible to identify “intentionality” (the “aboutness” of thoughts) or “qualia” (the “thusnesses” of experience) as nothing but brain states or behaviour.

In dealing with “intentionality”, Dennett, however, had a novel strategy – “first content, then consciousness” – that reversed the usual line of enquiry. He proposed “to understand how consciousness is possible by understanding how unconscious content is possible first”.

Nature, he argued, has its own unwitting reasons – “free-floating rationales” that are “independent of, and more fundamental than, consciousness”. The ability of organisms to respond appropriately, if unconsciously, to things in the environment is a “rudimentary intentionality”. And, over aeons, the “blind, foresightless, purposeless process of trial and error” has knitted “the mechanical responses of ‘stupid’ neurons” (in certain creatures’ brains) into a “reflective loop [that] creates the manifest illusion of consciousness,” he thought. “Mind is the effect, not the cause.” As spiders mindlessly spin webs, homo sapiens has spun “a narrative self”.

What Ryle had dismissed as “the ghost in the machine” could thus be exorcised, not by denying its existence but by seeing it for what it is – a conjuring trick rather than magic, an illusion fabricated by what (in his 1995 book Darwin’s Dangerous Idea) he called evolution’s “reverse engineering”.

Dennett’s first book, Content and Consciousness was published in 1969. Sixteen other books and numerous papers adapted and extended its thesis – that intentionality can be ascribed, along a spectrum with no clear dividing line, impartially to minds, human brains, bees, computers, thermostats: it is a functional relation between object and environment. As to exactly when, in evolutionary or personal history, conscious intentionality arose, “don’t ask,” he said.

We can take what he called a “physical stance” towards something (considering its constituents and their causal interlockings) or a “design stance” (seeing it as fabricated, by evolution or humans, to serve a particular function) or an “intentional stance” (explaining its behaviour in terms of goals that it would sensibly pursue if it were rational).

“The intentional stance is thus a theory-neutral way of capturing the cognitive competences of different organisms (or other agents) without committing the investigator to overspecific hypotheses about the internal structures that underlie the competences.” We treat chess-playing computers, some animals and humans, as if they had beliefs and desires. But, he was furiously asked, don’t we humans actually have them?

Yes and no, apparently. There is no one-to-one match between brain states and mental states. It is the creature as a whole that has intentionality. The discrete individually identifiable mental states that we seem to be having are (in reality) “an edited and metaphorialised version of what’s going on in our brains” – equivalent to “user illusions” on a computer screen: like the hourglass, folder and dustbin icons, they betoken the complex processes occurring behind the scenes.

“No part of the brain is the thinker that does the thinking, or the feeler that does the feeling,” said Dennett, nor is, or does, the brain as a whole. Instead there are “multiple channels in which specialist circuits try, in parallel pandemoniums, to do their various things, creating multiple drafts as they go” – until, from among “concurrent contentful events in the brain … a select subset of such events ‘wins’ … The way to explain the miraculous-seeming powers of an intelligent intentional system is to decompose it into hierarchically structured teams.” These consist of “relatively ignorant, narrow-minded, blind homunculi that produce the intelligent behaviour of the whole”.

“Yes we have a soul but it’s made of lots of tiny robots” was the headline of an article about him in the Italian newspaper Corriere della Sera, and Dennett endorsed it with amusement. He loved making furniture, building fences, mending roofs, tinkering with cars and boats; and, among the many things he constructed were sets of nested Russian dolls to illustrate his philosophy. The outside doll was “Descartes”; inside that was “the Middle Ghost” (a reference to Ryle’s) – but inside that was a “Robot”. “We are not authorities about our own consciousness,” he said. The robot is masked by the ghost.

Dennett pronounced qualia to be illusions. Ever since Descartes, we have tended to assume that we have “mental images”, as if, said Dennett, we could view little pictures, visible only to ourselves in an inner “Cartesian theatre”.

If so, we should be able to count the number of stripes on the tiger we are imagining, and say whether we have been seeing it face-on or sideways. No such definite information is available. Mental images are indeterminate in a way that pictures cannot be, and closer to generalised linguistic descriptions. So limited and poor is our access to our own conscious experiences, said Dennett, that it “does not differ much from the access another person can have to those experiences – your experiences – if you decide to go public with your account”. Indeed “our first-person point of view of our own minds is not so different from our second-person point of view of others’ minds”. We take an intentional stance on ourselves.

Dennett’s views remained pretty consistent throughout numerous books and papers, but in recent years he became more lenient towards mental imagery. He was impressed by neuroscientific research suggesting that there are specific observable brain activities that potentially may be decoded as imaging processes.

And, having been stern in denying what is disparagingly called “folk psychology” (a term he invented), he began to describe himself as “a mild realist” about mental states, prepared to concede that “the traditional psychological perspective” is not merely something described by third-person observers.

Avoiding accusations that he smuggled in the subjectivity he so adamantly denied, Dennett had recourse to “memes”, a concept (invented by Dawkins) modelled on that of genes. Memes are units of cultural practice, including anything from language to drama to wearing a baseball cap backwards to clapping as a form of praise. They are, in Dennett’s words, ‘“prescriptions” for ways of doing things that can be transmitted to, and from, human brains, and that “have their own reproductive fitness, just like viruses”. We are infected by memes, and it is “the memes invasion … that has turned our brains into minds”.

Dennett also applied a Darwinian approach to free will. “A billion years ago, there was no free will on this planet, but now there is. The physics has not changed; the improvements in ‘can do’ over the years had to evolve.” We are now able to predict probable futures, and to pursue or avert them. We are not deluded about having that capacity; as we are, he fulminated, about religion. Breaking the Spell (2006) was judiciously named. That was what he was urging religious people to do.

Born in Boston, Dennett spent the first five years of his life in Lebanon. His father, also Daniel, was a counter-intelligence officer posing as a cultural attache to the American embassy in Beirut. He died in a plane crash in 1947 (later, Dennett’s sister, the investigative journalist Charlotte Dennett, would claim Kim Philby’s connivance in it). Dennett’s mother, Ruth Leck, a teacher and editor, took the children back to Massachusetts.

Reprieved from matching up to his father’s expectations, Dennett said, he nonetheless grew up in his father’s shadow. But little could sap his exuberant self-confidence. Characteristically, the title of his 1991 book was Consciousness Explained.

In 1959, having just begun a maths degree at Weslyan University, Connecticut, Dennett read Willard van Orman Quine’s From a Logical Point of View. He was so excited that he decided “to be a philosopher, and go to Harvard and tell this man Quine why he is wrong”. The first two he managed, though for a time he worried that Quine (later a great friend) was more interested by Dennett’s sculpture than his philosophising.

Dennett did contemplate being a sculptor, and would, he said, certainly have studied engineering had his family not been so arts-oriented. Co-director of the Center for Cognitive Studies at Tufts University in Massachusetts, in 1993 he joined the Humanoid Robotics Group at the Massachusetts Institute of Technology to construct a robot (Cog) that would be not only intelligent but conscious. The project ended in 2003, and Cog was retired to a museum.

Dennett was Austin B Fletcher professor of philosophy at Tufts, and visiting professor at a host of other universities, including Oxford and the London School of Economics. His memoir, I’ve Been Thinking, was published in 2023.

He and his wife, Susan (nee Bell), whom he married in 1962, lived in North Andover, Massachusetts, and he also hobby farmed in Maine for more than 40 summers, blissfully “tillosophising” on a tractor, sailing his boat Xanthippe, fixing buildings and digging drains. Dennett loved solving puzzles and disinterring the inner workings of machines – above all those of “the miraculous-seeming” mind. “No miracles allowed,” he said.

He is survived by Susan, a daughter, Andrea, and son, Peter, and six grandchildren, and his sisters, Cynthia and Charlotte.

• Daniel Clement Dennett, philosopher, born 28 March 1942; died 19 April 2024