‘If universities had been an invention of the second half of the 20th century,’ Michael Dummett wondered in his last book, The Nature and Future of Philosophy (2010), ‘would anyone have thought to include philosophy among the subjects that they taught and studied?’ Dummett’s anxiety wasn’t whether philosophy could survive at a time when the value of a university education is gauged in increasingly reductive, economic terms. He was worried about the status of philosophy as an intellectual enterprise. ‘Philosophy is a sector in the quest for truth,’ he wrote, and if it ‘makes no progress, it is not worth wasting any time on’. Yet he remained optimistic, ending the book with the prediction that philosophers will ‘settle what is surely the most important question, whether there are rational grounds for believing in the existence of God … in the lifetimes of our great-grandchildren’. Not long to wait.
Others are less sanguine. The history of philosophy can be cause for dismay. We are, after all, still asking questions Plato asked 2500 years ago. What is knowledge? What is justice? What is a name? In the ‘linguistic turn’ of the mid-20th century, such inquiries were interpreted as calling for investigation of the meanings of words: ‘knowledge’, ‘justice’, ‘reference’. But philosophy has since reclaimed its essentialist roots. When contemporary philosophers ask ‘What is knowledge?’ they are interested in knowledge itself; studying the verb ‘knows’ may or may not be a step along the way. Their answers take the form of what the metaphysician Cian Dorr calls ‘identifications’, attempts to define the essential nature of knowledge by completing the Platonic formula: ‘To know something is …’ Is knowledge true belief acquired by reliable means? Is it truth that one can justify to oneself? Is it something else altogether?
There is nothing radically new in such philosophers’ methodology. They still test their answers against hypothetical cases. When Plato asks, in the Republic, whether justice is a virtue, he introduces one of the most famous thought experiments of all. In the myth of Gyges, a shepherd finds a ring that can make its wearer invisible. Who would not murder, rape, and steal, we are asked, if they could easily get away with it? According to Thrasymachus, in Plato’s dialogue, the idea of justice as a virtue is a scam that the powerful perpetrate on the weak. Socrates spends the rest of the Republic arguing that he is wrong.
The thought experiments in recent philosophy are no different in kind, though they are sometimes more bizarre:
While he sleeps, a man is subjected to unsolicited neurosurgery. A device is inserted into his brain that will influence his thoughts so that he has spontaneous true beliefs about the ambient temperature. He has no idea that this is happening. Some time the next day he thinks to himself: ‘It is 74 degrees.’ Does his belief amount to knowledge?
A woman whose body is snow white grows up in a black and white room, reading book after book about the physics and psychology of colour perception. On the day she finally leaves the room, she sees a ripe tomato and is stunned. Has she learned something new?
Walking by a railway, you see a runaway train carriage hurtling down a steep hill towards five people, who are trapped on the tracks. You notice a lever that will switch the carriage onto another track, on which a single person is trapped, as mysteriously as the other five. The carriage is sure to kill whomever it hits. Should you pull the lever or not?
Reflection on these episodes of pedagogic flash fiction has not produced consensus on the questions they are taken to address. Is knowledge anything more than reliable belief? Does the world transcend its scientific description? Is it wrong to kill an innocent person in order to save a greater number? Yet despite this apparent lack of progress, professional philosophers continue to draw their salaries. Is the idea of philosophy as a sector in the quest for truth, like justice for Thrasymachus in Plato’s Republic, nothing but a scam?
The surprise is not that the challenge should be made – ‘As long as there has been such a subject as philosophy,’ Bernard Williams once pointed out, ‘there have been people who hated and despised it’ – but that it so often comes from within the discipline itself. The fifth column has included Hume, who instructed us to ‘commit to the flames’ any work of inquiry that ventures beyond the bounds of quantitative and experimental reasoning; A.J. Ayer, who insisted that much past and present philosophy is unverifiable nonsense; and, more recently, Daniel Dennett, who indicts the discipline as largely ‘self-indulgent, clever play’. In almost every case, the philosopher who criticises philosophy wants his colleagues to redirect their intellectual efforts away from the ineffable, nonsensical or confused towards more worthwhile endeavours; a methodological revolution is announced, through which philosophy will make progress at last. The latest to make the attempt is Edouard Machery, in his astute and elegant book Philosophy within Its Proper Bounds.
Machery is a leading figure in ‘experimental philosophy’, a movement that approaches philosophical questions with the tools and results of empirical psychology. In particular, experimental philosophers have been interested in people’s actual responses to philosophical thought experiments, and how those responses vary from country to country, or between people who speak different languages, or have different ages and genders, or when cases are presented in different ways. They have found a disquieting degree of variation. The upshot, as Machery sees it, is that philosophers should abstain from the method of cases. Hypothetical scenarios are no way to test identifications: for instance, we are in no position to say whether the man with the thermometer in his head knows the temperature or not, so his imaginary case is no test of the equation between knowledge and reliable belief. Since we have no other way to confirm identifications, we should stop making them. ‘We cannot know whether pain is identical to some complicated neural state,’ Machery writes, nor can we know ‘what knowledge really is’ or ‘what makes an action morally permissible’. No more footnotes to Plato: philosophers must find more productive things to do.
What are we up to when we ask what is true in some contrived scenario? Whatever it is, you can observe it in yourself as you look back at the examples above. Does the man know that the temperature is 74 degrees? When she looks at the tomato, does the snow-white scientist learn something new? Should you pull the lever, so that the train switches tracks? When philosophers explain how we answer such questions, some say we rely on mysterious intuitions; others think it’s a matter of linguistic competence or a priori judgment. As Machery argues, none of these accounts is right. Our reactions to thought experiments are simply beliefs. They have no special connection with linguistic or conceptual mastery and they often draw on empirical background knowledge. The judgments we make in philosophical cases are continuous with the judgments we make in everyday life.
If that is so, the defensive philosopher will complain, you can’t object to the method of cases without inviting scepticism about ordinary judgment. But Machery is no sceptic. As he sees it, the problem with the method of cases is that it takes our ordinary power of judgment into extraordinary realms. His concern isn’t with everyday beliefs but with unusual cases. It is understandable that philosophers focus on such cases, since competing theories of knowledge or morality often agree about more mundane examples. It’s the unusual cases that hold out the promise of a test. For Machery, though, the promise is deceptive. Here, his critique rests on two lines of evidence. First, different groups give systematically different verdicts on philosophical thought experiments, which sometimes diverge from the consensus among philosophers. Second, a single individual may give different verdicts on a case depending on how it is presented to them.
Machery patiently catalogues the pertinent empirical data. Among the striking results is that verdicts on the ‘trolley problem’ – what to do about that runaway train carriage – vary from the US to Russia to China: 81 per cent of Americans think you should pull the lever, killing one and saving five; only 63 per cent of Russians and just over half of Chinese participants agree. The vast majority of Tibetan monks think it permissible not merely to pull the lever, but to push someone in front of the train carriage, ending their life, if that is the only way to save the others. Reflecting on these results, along with the divergent responses to examples involving knowledge and reference, Machery concludes that ‘there is no reason to prefer one of the answers elicited by cases to the other; as a result, we should suspend judgment.’
This is a puzzling argument. ‘Philosophers have not taken the measure of how much disagreement there is about these cases,’ Machery complains. But we see plenty of disagreement in the seminar room. Machery doesn’t explain why disagreement about cases should be more disturbing than any other kind of disagreement between philosophers, as when they make conflicting claims about the nature of knowledge, the mind-body problem or the demands of ethical life. The discipline is, after all, nothing without disagreement: when a question is settled to the satisfaction of all, philosophy leaves it behind. If disagreement is disturbing, we do not need the detour through empirical psychology to see that we are in trouble: pointing to the state of philosophical theory should be enough.
In fact, it isn’t clear that we must respond to disagreement, whether it’s about cases or theories, by giving up our own beliefs. Predictably, this too is something about which philosophers disagree. ‘The leading views support the claim that, when philosophical cases elicit disagreement among epistemic peers, they ought to suspend judgment,’ Machery asserts, but he provides no survey data to back this up. Leading or not, it is a common view among philosophers that reasonable conviction can survive the disagreement of peers. Such disagreements are often asymmetrical. One side has reasoned well or exercised good judgment; the other has not. Naturally, both sides will think their reasoning was sound, and there may be no independent test to determine who is wrong. But the absence of such a test doesn’t prevent us from maintaining that those who reasoned well should stick to their guns and insist that they are right. The enlightened may be unable to prove their view to the satisfaction of the unenlightened. But so it goes. Reasoning well is one thing, persuading your critics is another.
One of the most notorious revolutions in philosophical method was logical positivism, channelled into Language, Truth and Logic by a young A.J. Ayer. Ayer proclaimed the verification principle: that only statements open to empirical verification can be meaningful. It didn’t take long for critics to notice that the verification principle cannot be empirically verified. Likewise, Machery may believe that we should suspend judgment in the face of stubborn, intelligent, well-informed disagreement, but it won’t take long for critics to point out that this claim is subject to stubborn, intelligent, well-informed disagreement.
So much for inconsistency with others. Some of the most striking discoveries of experimental philosophers concern the extent of our own personal inconsistencies, as we respond differently to the same case when it is presented in different ways. If we are asked about the man with the thermometer in his head after being presented with a case in which knowledge is clearly demonstrated, we are likely to deny that he knows the temperature. If by contrast we are first asked whether someone knows the temperature when they get it right on the basis of a lucky guess, we are likely to give the thermometer man more credit. Similarly, how we respond to the trolley problem is affected by the details of the version we are presented with. It also depends on what we have been doing just before being presented with the case. After five minutes of watching Saturday Night Live, Americans are three times more likely to agree with the Tibetan monks that it is permissible to push someone in front of a speeding train carriage in order to save five. And there are ‘framing effects’: with the trolley problem, for example, we are more likely to conclude that you should pull the lever when the case is described in terms of saving lives, not causing deaths.
There are delicate issues here about what counts as superficial framing and what could make an ethical difference. At one point Machery suggests that in cases where you are told you could save someone’s life it is a matter of mere framing whether they are involved in an unforeseeable emergency or threatened by a chronic situation such as famine, or whether the person who will die is related to you or not. It doesn’t take great imagination to see that these changes potentially matter. But Machery is no fan of reckless imagining. ‘The influence of superficial features on judgment shows that it is a bad idea to hone one’s moral sense against works of literature,’ he remarks in passing. ‘Their rich narrative content is likely to lead judgments astray.’
Machery claims that ‘philosophers only occasionally consider different versions of the same case to sieve any influence their superficial content may have, and they never do it systematically.’ He is largely right about what appears in print. But I worry that he has been taken in by the conventional image of philosophy as armchair reflection. The reality is that most philosophers inhabit a crowded agora: the department lounge or common room in which dozens of cases, with variations major and minor, are tossed back and forth. Not systematic, perhaps, and not deliberately designed to eliminate order and framing effects, but well suited to doing so. Our practices should no doubt improve, but the change required is incremental, not revolutionary. The method of cases will survive.
‘It is always a significant question to ask about any philosopher: what is he afraid of?’ Iris Murdoch wrote in The Sovereignty of Good (1970). In Machery’s case, my guess is that he is afraid of wasting time. He wants philosophers to give up on questions they don’t know how to answer and take up questions they do. He thinks we should be in the business of analysing concepts understood as psychological artefacts. We can study default beliefs with the tools of empirical psychology. For instance, Machery finds that people tend to make the unfounded inference that because something is universal it must therefore be innate, and that because it is innate it must be functional. Our cognitive and linguistic processes exploit false information. If you protest that this is psychology, not philosophy, Machery has a quick response: ‘We should not be too concerned with whether an issue is philosophical or not, just with whether it is interesting!’ But for some of us, whether a project counts as philosophy is an existential question: livelihoods are at stake.
Machery accuses other philosophers of ‘historical myopia’ for drawing lines between empirical psychology and philosophy. He urges a return to David Hume and William Whewell, for whom the two fields were one. ‘For much of the history of philosophy,’ Machery writes, ‘philosophers could not have imagined their philosophising as separate from not only mathematics, but also the empirical sciences.’ He goes on to make an alarming conjecture: ‘Perhaps because they felt threatened by the apparently unstoppable growth of the sciences, philosophers started carving their own kingdom, far removed from scientists’ interests and methods.’
It would take a lot of historical spadework to support this portrayal of philosophers fleeing from science in search of intellectual and academic turf. Machery does not provide it. He is right that philosophy was not originally distinct from science: it was the search for systematic understanding of the world. In Western philosophy, this conception survived, more or less, through the 17th century, when the natural sciences were transformed by such philosophers as Bacon and Descartes. ‘Philosophy’ became a term for the inquiries left behind when disciplines work out their proprietary methods. Thus psychology hived off in the 19th century, with William James and Wilhelm Wundt picking up on threads in Hume. Economics did the same with hints from Adam Smith, and sociology with Comte and Marx in the 19th century and then Durkheim at the beginning of the 20th. Computer science and linguistics established themselves outside philosophy around the 1950s. In each case, the origins of these disciplines were philosophical; they ceased to be philosophy when they gained methodological traction.
This conventional narrative is in need of refinement. As it stands, it is too simple and too linear. Where do history and anthropology fit in? What about the interpretative study of literature, music and visual art, some of whose methodologies may count as philosophical? There is a need for careful reflection – philosophical reflection – on the very idea of a distinctive method. But whatever the details, the result is a Catch-22: as soon as philosophy makes progress by means that constitute a discipline, it is no longer philosophy.
This creates a problem of public relations. But the issues with Machery’s circumscription of inquiry are more fundamental. To dismiss questions we don’t know how to answer is deeply anti-philosophical. Indeed, if you had to say what philosophy is today, a first approximation would be: the systematic inquiry into questions that seem profound but are as yet unanswerable, in that we haven’t identified methods for addressing them that elicit rational convergence. We shouldn’t overstate our epistemic frailty. If rational belief can survive peer disagreement, as I have suggested, then an inability to convince others is consistent with knowing the truth oneself. And new disciplines are bound to emerge as philosophy moves forward. Philosophers should not be embarrassed by these things; instead, they should spread the word. The patience to ask and to keep asking questions, without the assurance of agreement or the availability of methods apt to elicit it, is the philosopher’s gift. It is an expression of intellectual hope, and the repudiation of philosophy is a counsel of despair.