Don’t be fooled by the title; there is little about bacteria, only a brief digression about Bach, and no “back” in philosopher Daniel Dennett’s latest Big Bravura Book about consciousness. But, as he confesses, he is an Author who Adores Alliteration. And Capitals. And Neologisms. He has also written several books about mind, consciousness and evolution, so it is fair to ask whether he has anything new to say in what the blurb claims is his “masterwork”. If my answer is “well, sort of”, it is important to be upfront about the fact that Dennett and I have not always seen eye-to-eye. Indeed, a German magazine once digitally edited together pictures of us sparring as bare-knuckle boxers. Despite this, and although he may well not thank me for it, there is much here that I agree with.
Dennett is one of those American philosophers of mind, so unlike most of their British counterparts, who is comfortable conversing with and responding to the work of evolutionary biologists and cognitive scientists. His heroes, cited frequently here, are Charles Darwin and Richard Dawkins in biology, Alan Turing and Claude Shannon in artificial intelligence and information theory. His enemies are creationists and mysterians in general, philosopher John Searle, polymath linguist Noam Chomsky, and biologists Stephen Jay Gould and Richard Lewontin. His aim is to provide a materialist account of the evolutionary origins of the human mind and consciousness by way of an extension of gene-based natural selection into human culture through the invocation of memes, that seductive Dawkinsian concept of which more below.
Bacteria to Bach and Back is an infuriating book. It is too long, repetitive, indulgently digressive and self-referential (no fewer than 64 references to his own publications). But underlying it all there is a subtle and interesting argument. The bare bones are these: mind and consciousness are no more and no less mysterious than other natural phenomena, such as gravity. Granted the right chemical and physical conditions, life forms will emerge from the primeval slime, and granted the right conditions, life will evolve large-brained organisms such as humans – who are profoundly social animals and hence need to be able to communicate, cooperate and compete with their fellows. This requires the ability to think, remember, plan, empathise – in a word, to have a mind. And minds require large and complex brains to enable and sustain them, all generated by Natural Selection.
The capitals are important; they emphasise a point Dennett repeatedly makes, stealing the clothes of the creationists, that Natural Selection is an Intelligent Designer, constantly improving life forms through the blind Darwinian processes of favouring fitter, better adapted variants and winnowing out less fit ones. From the very origins of life, Natural Selection generates Intelligent Design, producing organisms that show competence without comprehension. Both an amoeba retreating from a noxious stimulus and, say, a room thermostat are competent in this sense, without comprehending the reasons for their actions. In his ultra-Darwinist commitment, Dennett will have no truck with the famous Gould/Lewontin argument that many seemingly designed adaptations are not selected for, but are the inevitable consequences of, structural physical constraints. He is, however, a little more forgiving of Gould’s “exaptations”, features serving one function but available for others, such as the dinosaur heat-regulating feathers co-opted into necessary flight aids as birds evolved.
As a philosopher, Dennett is not interested in the specifics of the evolutionary path that has led to humans, of when competence becomes comprehension. There is no shortage of books by evolutionary-minded neuroscientists – neurologist Antonio Damasio is among the best, though curiously ignored by Dennett. Damasio charts the origins of nervous systems and the emergence and increasing complexity of brains, from single-celled creatures through to primates and hominids, seeking to locate within this evolutionary pathway the first appearance of sensations of self-awareness, emotions and memory, the precursors of mind and consciousness. It is enough for Dennett that one can trace a plausible story for these transitions.
In naturalising consciousness he takes issue with the “new mysterians”, who claim an irreducible distinction between the qualia of subjective first-person experience – seeing and experiencing the colour red, for example – and the third-person “objective” viewpoint of external observers, who can specify the exact wavelength of the red light but can never know whether their experience of it is identical to yours. For Dennett this apparent irreducibility – philosophers call it “the hard problem” – is a false distinction. Consciousness is a system property, and is not reducible: he takes issue with those hard-line molecular biologists, notably DNA pioneer Francis Crick, who seek to locate consciousness in particular ensembles of neurons in specific brain regions. Such ensembles, Dennett argues, are mini-robots, competent in their functions, but only their interactions within the totality of the brain enable comprehension, and with it the “user illusion” that we all share, of being a person in charge of these processes. I like the competence/comprehension distinction, though I doubt if Dennett thought he was merely an illusion when he wrote this book, any more than I believe I am when reading it.
For Dennett, the evolutionary transition to comprehension and consciousness comes with the emergence of the first humans, and above all with the appearance of language, always the greatest stumbling block for evolutionary theorists. Here, his principal target is Chomsky, who has always insisted on the uniqueness and universality of human language. As Chomsky points out, language is unlike any other evolved human feature. Nowhere does one find precursor proto-languages; all seem fully formed and complex. Dennett claims that Chomsky evades the evolutionary question, dismissing much of the last decade of his work, culminating in 2015’s Why Only Us?, a book in which Chomsky concludes, improbably, that human language must have emerged in our hominid ancestors through one single giant mutational leap, making it possible to find the words to express private thoughts. It is far more probable, Dennett argues, that the origins of language lie in the social nature of humans and come from the necessity of communicating with one another in proto-languages now lost.
Which brings us to his claim that for humans, slow biological evolution has been superseded by fast cultural evolution. This too advances through natural selection, and the agents on which such selection operates are memes, the cultural analogues of genes. Memes are, for Dennett, units of cultural transmission. They inhabit a person’s mind and replicate like viruses by infecting other minds. Natural selection filters out weak memes, and speeds the dissemination of strong ones, thus vastly speeding cultural change.
The problem is that a meme can be almost anything: a fashion for wearing your baseball hat backwards, a word, a snatch of music, a political affiliation, a comedian’s catchphrase or how to shape a stone axe. Where a gene is – more or less – a specific DNA sequence with an equally more or less defined biological function, memes can be whatever you choose. It is a term so vacuous, despite its regular appearance in dinner party chatter, that it has its philosophical and biological critics unable to choose between indignation and helpless laughter. Dennett realises this and devotes a chapter to responding to his critics. I could – just – condone his enthusiasm if he regarded memes as metaphorical, but he categorically denies this. A word, he insists, in his account of the origins of language, is merely a meme that can be pronounced.
Such vacuity makes the meme concept theoretically useless as a tool for understanding cultural evolution. Nor does Dennett actually require memes for his indisputable claim that cultural evolution depends on humans’ sociality and cooperativity. His final chapters see culturally evolved modern humans as themselves intelligent designers, creating a future shaped by the power of the artificial intelligences we have created. Civilisation, he reminds us, is a work in progress. It may die, returning the planet to the bacteria, or, if human sociality can transcend our current problems, it can thrive. The future is open.
• Steven Rose is, with Hilary Rose, the author of Can Neuroscience Change Our Minds? To order From Bacteria to Bach and Back (Allen Lane) for £18.75 go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over £10, online orders only. Phone orders min p&p of £1.99.
