If philosophy is the love of wisdom and concerns itself primarily with how we should live, then one might reasonably infer that true philosophers are wise and good people, able to help others who are struggling with tragedy or just with being. But on the whole that’s not how philosophers are perceived. I have academic philosophers in mind, even though I know that bestowing the title “philosopher” only on people in virtue of their being employed as academics in state-funded universities would be rather ridiculous. There are many great sages and sophiaphiles outside of philosophy departments. The position of academic philosopher is a relatively recent innovation, and one might regard the professionalisation of the subject as inexorably corrupting and distorting, especially in the contemporary academy in which intellectually bogus managerial and administrative ideas are ubiquitous – witness “research themes”, “impact”, and the proliferation of “research strategies”.

However, recent complaints about the specialisation of philosophy seem not to have professionalisation as their target, but rather the inaccessibility of what the professionals are doing from the point of view of outsiders. Professionalisation and inaccessibility may be related. Is it because professional philosophers are so specialised that they are hopeless at helping people live and at engaging with the lay population’s search for meaning and an understanding of philosophy?

Whether they are professional or not, philosophers love to argue, even if they are arguing about whether or not they are arguing. I once heard two eminent philosophers discuss exactly when Wittgenstein’s Tractatus becomes nonsense. One of them insisted that they both thought the same thing about this matter, and the other argued that there was a residual disagreement between them. For all I know they are still corresponding about it now.

There is no better argument for philosophers to have than about the nature of philosophy itself. To argue about the nature of philosophy is to get to the essentially ridiculous nature of the subject. If philosophy is at worst (or perhaps at best) the useless questioning of things that other people take for granted – whether we know the sun will rise tomorrow or whether there are tables or whatever – what could be more useless than arguing about whether philosophy itself has any use? Of course, as a young Alan Bennett said to Jonathan Miller in a comedy sketch parodying Oxford philosophy, someone who asserts that metaphysics is impossible is in fact advocating a metaphysical view. Similarly one cannot pronounce on what philosophy is, or even offer an argument for why it is useless, without doing philosophy. Philosophy, like writing prose, is easily done unwittingly.

I want to explain why I think that much of the specialisation of contemporary philosophy is not a bad thing after all. In large part my argument depends on the engagement of philosophy with rest of knowledge. I want to defend the specialisation in philosophy that is a consequence of the overlap between a subfield of philosophy and another specialised subject matter, where that may be the history of philosophy itself. This is the kind of philosophy that I am most sure is worthwhile. If there is a kind of pure philosophy that may not be valuable, it is not clear that it is anything more than an ideal form anyway, since no philosopher is an island.

Either way, it is important to distinguish between different kinds of specialisation. Some people specialise in the literature that their peer group has produced over the last 20 or 30 years, and have little knowledge of what the great philosophers of the past have said, even about their own preoccupations. This may often be a bad thing. Even worse, every subject has its blind alleys, and there are doubtless branches of philosophy with concepts and questions that we will come to see as pointless. However, it is no easier to pick winners in philosophy than in any other area. We know that the overall contribution of philosophy to human existence is so great as to be impossible to evaluate even if we only consider its spin-offs in science. This contribution comes from a subculture that thinks in a sustained and careful way about something that others take for granted, and this usually means specialising. I must confess that my defence of specialisation is motivated by my earnest wish to be allowed to spend the rest of my life thinking largely about the same nexus of issues that I have been thinking about for 20 years – although in my view that also means learning more about everything else too.

Certainly, academic philosophy can be highly specialised, and discussions often take place in what the outsider would regard as impenetrable jargon. However, this situation is not peculiar to philosophy. Who understands the terms in which mathematicians and theoretical physicists communicate, other than those with sufficient training in the relevant technical areas? There is supposed to be something wrong with philosophy in particular being inaccessible, and perhaps this is because it seems to betray the Socratic conception of philosophy mentioned at the start of this essay.

Socrates thought that his life’s purpose was to show others that those who profess to have knowledge of what is most important do not have it after all. However, for Socrates what is most important is the nature of virtue, which for him means knowledge of how one should live. But philosophy did not begin with Socrates. Thales is often called the first philosopher for asking what everything is made of and defending the prima facie implausible answer, water. Doubtless he was not really the first person to enquire into being, and thinkers from pre-history may also have engaged in metaphysics. It may be that the ultimate philosophical question is about the meaning of life, but it is rivalled in importance by questions concerning the nature of the universe. Furthermore, there are many philosophical questions – concerning, for example, personal identity, free will, knowledge, and the nature of the emotions – that are closely related to the meaning of life, but one might be interested in them independently of the bearing they have on it.

Philosophy is unified, if at all, by its methodology and ultimate purpose. The different areas of philosophy are distinguished by their different subject matters, and each one overlaps with the theoretical discourse of other subjects. There is no such thing as fact-free thought, except perhaps in logic and mathematics. Philosophical debates concern both aspects of human subjectivity (such as agency, identity and responsibility), and the nature of features of the world (such as causation, chance, law, matter, modality, space and time). It would be absurd to engage in philosophical reflection on human subjectivity in complete ignorance of history, politics and psychology, to say nothing of works of art, literature and music. Similarly, it is absurd for philosophical inquiry into nature to be conducted in complete ignorance of science. Hence, some philosophers must specialise in some parts of logic, mathematics and science, and bring their knowledge to philosophical debates with their colleagues. Now that philosophical inquiry has born the fruit of contemporary mathematical logic, and produced sophisticated systems of deontic, epistemic and modal logic, it would be folly to suggest that philosophical debates about philosophical logic – as well as ancient questions concerning essence, existence, identity, individuality, properties and so on – should be conducted among experts in an idiom that is accessible to the layperson.

A. C. Grayling points out, in an interview with tpm (issue 26), that Russell expected to be read by his economist friends and others at Cambridge, but those people would have had an advanced training in mathematics and abstract thought. Many philosophers work in areas that overlap with the most theoretical parts of science or with the history of science. For example, some philosophers work on probabilistic theories of rationality and causation, as well as decision theory, confirmation theory, theoretical linguistics, formal and machine learning, the foundations of physics, and so on. These people interact with people in the sciences who are interested in those areas. I have been to many conferences that include both physicists and philosophers, and my colleagues work with biologists, computer scientists, economists and psychologists. If the philosophers weren’t specialists, they wouldn’t be able to interact with the scientists.

For those philosophers who want to understand traditional questions about the mind or the physical world in the light of our best scientific knowledge, it is much easier for them to talk to scientifically literate people about their work, because the problems are generated by actual science and its conceptual and mathematical complexity. The same is true for people concerned with the philosophy of music, aesthetics and so on. Philosophy also tends to require some knowledge of the history of ideas, the history of science, and political and economic history. The history of art and literature are completely intertwined with the history of philosophy too. A lot of philosophy is simultaneously history of philosophy, for philosophers are constantly presenting and interpreting each other’s arguments. Some of the best arguments were considered in some form by the great philosophers of the past, but again, to understand well the history of philosophy or even small parts of that history, it is necessary to specialise to some extent.

As I write there are those who question the worth of all areas of the arts and humanities and demand to know how they benefit the so-called general public. Who are the latter people? Some have no academic training at all and a relatively limited vocabulary pertaining to abstract concepts. To these people, much of the dictionary will be impenetrable jargon, so philosophical journals pose no unique problems. On the other hand, the academically initiated population will include people who have been to university, and those who have trained their minds themselves. There will be rough divisions between those who have mathematics and those who do not, and those who know most about the arts, the humanities or the sciences. Some of these people will already be used to thinking about the philosophical issues in their own fields, or at least will know enough about their subjects for their philosophical aspects to be easily explained to them.

Hence, I may find it very easy to explain what I work on in a reasonable amount of detail to a mobile phone engineer with a longstanding interest in physics, and my colleague may find it very easy to explain what he does to a cook who has read everything by Sartre and Camus. There would be something badly wrong if work in the philosophy of physics were as accessible to a linguist as to a physicist, or if work in the philosophy of language were as accessible to a physicist as to a linguist.

People want very different things from philosophy. Some may want to know whether physics has really explained the origin of the universe, others will want to know whether they should be vegetarians. Most will in the end have the idea that philosophy concerns itself with whether our existence has meaning and purpose, with the fundamental nature of reality, and the limits of knowledge. However, there is no low-hanging fruit to pick in these areas, so we content ourselves with making small steps in specialised debates, not by engaging with the big picture directly. Most professional philosophers study tiny issues because it is only through the details that the bigger picture is revealed.

I do not see why all philosophers, or even most, should be interested in communicating their thoughts about these matters to the world. I have no burning desire to compete with people who have made it their business to popularise philosophy, and even if I did I might well not be very good at it. There are a large number of popular books on philosophy, and there is a thriving market for them. There are many excellent people who mediate between academia in general and the rest of the population. I am baffled as to why people are calling for all academics to do these things. The case of philosophy is in this respect no different from that of pure mathematics or microbiology. The idea that every scientist should be a part-time science journalist and public speaker is absurd.

It is all too easy to mock and dismiss the recondite work of academics and question its value. When people claim that professional philosophers are producing work of little or no value because it is jargon-ridden and otherwise inaccessible, this may be telling people what they want to hear. If all that stuff in the journals is really unimportant to philosophy’s mission, then no need to feel bad about not understanding it, no need to accept that it is as out of reach as much of science, and no need to make the immense effort necessary to train one’s mind and acquire the background knowledge and master the concepts to the extent required to understand it.

Most academic work in all subjects is dry and dull to the outsider and contributes only a minute increment to the sum of knowledge. I expect there are people out there whose appetites for the details of snail morphology or monastic life in seventeenth century France is immeasurably greater than mine. I don’t expect them to be interested in the status of the principle of the identity of indiscernibles in the light of contemporary physics. A civilisation needs people whose curiosity about obscure matters is abnormal, if not borderline obsessive-compulsive. Charles Sanders Peirce spent hours every morning studying the Critique of Pure Reason. That is way over the top by the standards of most philosophers, because they don’t care that much about Kant. But we should all respect it just as we respect our colleagues who spend their lives trying to understand Joyce or the distribution of prime numbers, or when the Tractatus becomes nonsense, for these are all among the most important matters there are.

Philosophy is concerned with the foundations of thought and knowledge in every domain including, for example, logic, mathematics, and all the sciences, but also ethics, law, politics, and historiography, as well the critical study of art and literature. It is therefore unwise to expect the average academic philosopher to do justice to the subject as a whole. Rather, it is important that some people become specialised in understanding exactly why we do not know the answers to specific questions many of which make sense only to experts. This may not amount to advancing our understanding of the meaning of life, but it is in keeping with Socrates’ conception of the philosopher as gadfly, asking awkward questions and exposing epistemic hubris. Our knowledge of the world has grown immeasurably since ancient times, and philosophers would be failing in their role if they did not specialise sufficiently to know enough to be able to point out exactly where lie the limits of our understanding.

James Ladyman is professor of philosophy at the University of Bristol.