Considered by many to be one of the leading philosophers of the 20th century, Austrian- British Ludwig Wittgenstein (1889–1951), had a major influence on logic, logical positivism, as well as on the philosophy of mathematics, mind, and language.

John Searle is Slusser Professor of Philosophy and Mills Professor of Philosophy of Mind and Language at the University of California at Berkeley, and the author of numerous books on, among other subjects, consciousness, social reality, mind, language, and society.

Simply Charly: What were the prevailing branches and schools of thought in philosophy in the early decades of the 20th century, before Wittgenstein made his mark?

John Searle: Any answer that I give to this question is bound to be superficial because I cannot, in this space, cover the complexity of the history of philosophy of that period. But in very broad outline, it was something like this: In English-speaking countries, Hegelianism remained remarkably influential right into the 20th century. It was attacked quite effectively in England by G. E. Moore and Bertrand Russell. In the United States, it was replaced by the pragmatism of Charles Sanders Peirce, William James, and John Dewey. A development that occurred in the late 19th century was decisive for the subsequent history of philosophy, especially in the English-speaking countries, but it was not widely known until well into the 20th century, and that is the work of Gottlob Frege, a German philosopher, and mathematician. Frege revolutionized the subject of logic simply by inventing the predicate calculus, a form of logic that was vastly superior to traditional Aristotelian logic, and Frege’s logic has remained the standard logic to the present time. He also invented the philosophy of language as we now understand it by giving a more profound conception of language and meaning than anyone had given before.

In any case, Russell and Wittgenstein were both aware of Frege’s work and used it in their early work. Wittgenstein’s first book, the Tractatus Logico-Philosophicus (in German: Logisch Philosophische Abhandlung), was very much part of the Russellian project of trying to analyze the essential nature of language. Because the form of the analysis was to reduce the complex phenomena to simpler phenomena, Russell’s project became known as “logical atomism.” Wittgenstein’s work was not well known until the publication of his first book the Tractatus in 1922, but I think that from that point on, it was remarkably influential. I will say more about it later.

SC: Wittgenstein became interested in philosophy after studying mathematics first. How did his background in mathematics and logic influence his philosophical outlook?

JS: Strictly speaking, Wittgenstein was a student of engineering, not mathematics. When he was a student at Manchester, he became interested in the nature of the mathematics that he was using as an engineer, and he asked his teachers various questions about the foundations of mathematics they were unable to answer. But they told him that there was a man in Cambridge, Bertrand Russell, who worked on these issues in the foundations of mathematics. Wittgenstein then went to Russell. They had a series of discussions that convinced Bertrand Russell that Wittgenstein was a genius, and he encouraged him to pursue a philosophical career. Wittgenstein’s philosophical researches were interrupted because he served in the Austrian army in the First World War. And according to the legend, at least, he kept working on the Tractatus while he was actually at the Front and later in a prison camp.

He continued his interest in the philosophy of mathematics until the very end of his life, and according to some accounts (I am not sure if they are completely accurate), he regarded his book Remarks on the Foundations of Mathematics to be his most important contribution to philosophy. Certainly, the profession has not treated it that way. It is an important work but not as important as Philosophical Investigations.

SC: Tractatus is widely considered to be one of the most important philosophical works of the 20th century. But the Philosophical Investigations advances notably different philosophical ideas. Which of the two works, in your view, better represents the true essence of Wittgenstein’s thoughts?

JS: Wittgenstein’s later philosophy, as represented by Philosophical Investigations, is a much more influential and, in the long-run, a more important work than the Tractatus. The Tractatus is a powerful and elegant expression of a certain conception of language. Wittgenstein asked, “How is it possible for language to represent?” And his answer is that it is only possible because there is a certain isomorphism between the structure of the sentence and the structure of the fact represented by the sentence. There is a kind of matching relationship which makes language (and thought) possible at all. In the Investigations, he abandons the idea altogether that there is such a thing as the essence of language. There is just an indefinite variety of uses of language, which he called different “language games” that people play with language. So, it is not so much that he rejected the answer given by the Tractatus but that he rejected the very question. He once said in his later years that the Tractatus was like a machine that didn’t work or like a clock that didn’t keep accurate time, but, as he said, it is definitely not just a hunk of junk.

JS: Philosophy is not a monolithic field. Is there cohesiveness or at least common ground among different branches and schools of thought, or a total divergence of ideologies among them?

JS: Again, as with the first question, this does not admit of an accurate summary answer. But roughly speaking, the conception that most philosophers have today is something like the following: Internationally, there are two broad schools of thought or two broad ways of doing philosophy. These are called “Analytic Philosophy,” which is the sort of philosophy I do and which is dominant in English-speaking countries as well as some parts of Europe, and so-called “Continental Philosophy,” which is still influential and perhaps even dominant in large parts of Europe. Analytic philosophy is easier to characterize than Continental philosophy. The original idea of Analytic philosophy in its purest traditional form was that philosophy consisted primarily in the analysis of meaning. So the study of language was essential to philosophy in general, and indeed some analytic philosophers would have said that philosophy is simply a certain type of study of language. I don’t think many analytic philosophers would agree with that today but the idea that the aim of philosophy is analysis, to analyze the structure of language, thought, society, ethics, etc., is a dominant conception in Analytic philosophy. Continental philosophy is much harder to characterize, and there are many different strands. Hegel, Husserl, and Heidegger are very important figures in Continental philosophy, but they are much less important in Analytic philosophy. I will not try to summarize their views because I do not understand them well enough, and I do not think they write very clearly. There is, of course, some overlap between so-called Analytic philosophy and Continental philosophy. Both are interested in language, though usually from a very different point of view. So, for example, mathematical logic is very important in Analytic philosophy, but it has very little importance in Continental philosophy, where the study of literary uses of language is by many philosophers taken as central. One of the products of Continental philosophy is something called ‘Critical Theory.’

There is, of course, a kind of category mistake in dividing schools of philosophy by using terminology that opposes the methodological to the geographical. It is as if one said there are two kinds of things that go on in the United States, business, and Kansas. But all the same, this is the terminology that people currently use.

SC: Generally speaking, do different schools of philosophies reflect (and thus evolve with) the historical context in which a given philosopher lives, or do individual philosophies emerge based on the philosopher’s personal experience(s)? How does this pertain to Wittgenstein?

JS: All philosophy is historically situated, and no philosopher I know seriously believes that you can totally escape from the historical context in which you are working. Having said that, of course, philosophy, whether you like it or not, is always an expression of the intelligence and sensibility of individual philosophers. Characteristic of Analytic philosophy has been its concern with developments in science, mathematics, psychology, and other disciplines, and indeed for most analytic philosophers, there is no sharp distinction between philosophy and other disciplines. Now Wittgenstein, I believe, was very much opposed to the scientism that characterized intellectual life generally, and he thought that philosophy ought to be pure; it ought not to be an extension of science by other means. He thought that philosophy had a special domain in which there should be an attempt to solve puzzles that are generated by a failure to understand the actual operations of language. “Philosophy is a battle against the bewitchment of our intelligence by means of language,” he wrote. He thought that it was a terrible flaw in our culture that we believed science was the right model for all knowledge and understanding. So Wittgenstein was a child of his time, and was shaped by a distinctively European set of experiences, but he had an original and powerful vision of philosophy and of its importance in human life, and he opposed what he took to be the worship of the sciences he thought was part of our modern sickness.

SC: A somewhat related question: In an interview with Boston Globe last year, you said that in the 17th century, the theory of knowledge was the core of philosophy. But now, the center of philosophical debate is philosophy of mind. Is there a way of predicting philosophical trends of the 21st century?

JS: I honestly think there is no way to make such predictions. But one can give a statement of one’s intentions about one’s own future, and I can tell you what I do and what I intend to keep doing. I think the central question in philosophy today is how to reconcile a certain conception that we have of ourselves with what we know for a fact about how the world works independently of us. We have a pretty adequate conception of the physical features of the world from physics, chemistry, and other so-called hard sciences. But at the same time, we have a conception of ourselves as mindful, conscious, rational, free-will having, speech act performing, political, aesthetic, and ethical beings. How do these two relate? How do we get an account of the human reality which is not only consistent with but shows it to be a natural development of the basic facts as described by the hard sciences? Though I was working on this question for years without knowing that this was the question I was working on, I think it is the central question in philosophy today. Most of my important work has been dedicated to addressing different aspects of it. So, for example, for me, one aim of the philosophy of language is to show how language is a natural biological phenomenon. Similarly, the philosophy of mind that I work on advocates an overthrow of the traditional distinction between mind and body. There is just the world we all live in and among its basic physical features are neurobiological processes capable of causing and sustaining consciousness and intent. I think these questions will continue to obsess philosophers for the coming decades, but no one should pretend to predict what is going to be the dominant philosophical trend of the 21st century.

SC: How do today’s philosophers like yourself determine who the “greatest” philosopher of all time had been? Is this a purely subjective call based on your own affinities, or is there a common agreement borne out of a philosopher’s contributions and advancement of knowledge?

JS: I don’t think it is useful to worry about who was “the greatest philosopher of all time.” We are not, in this profession, issuing prizes. All the same, in the Western philosophical tradition, there are certain people of such towering achievement, that they cannot be ignored or neglected by anyone who cares about this subject. Three towering geniuses in this tradition are Plato, Aristotle, and Kant. What made them so important? Well, I would say it was three features: One is that they simply had stunning philosophical intelligence. The second is that they had a comprehensiveness, unusual in philosophy. That is, each of those three philosophers essentially addressed all, or nearly all, of the main areas of philosophy. A third feature that is harder to characterize exactly, is that each had a kind of profundity. Each addressed questions in a way that went beyond the surface manifestation and tried to get to the bottom of the issues.

For sheer intelligence, probably the most intelligent philosopher who ever lived and perhaps the most intelligent human being who ever lived was Gottfried Leibniz. But Leibniz’s actual doctrines are extremely implausible. And though he made important contributions to a lot of fields (for example, along with Newton he invented the calculus), his purely philosophical work is today regarded as mostly of historical interest.

Wittgenstein was a very great philosopher, but he is not in the same class as the people I mentioned. For example, his work is not comprehensive in the way that most of the great giants of the past were. He has very little to say about ethics and political philosophy, for example.

SC: Who are some current philosophers whose thinking has been heavily influenced by Wittgenstein’s, and also, how relevant are his theories in the 21st century?

JS: Wittgenstein’s influence is pervasive, but it is often indirect. People have a certain sensitivity about language which they would not have had without the work of Wittgenstein. But at the same time, they don’t practice the study of language in a way that Wittgenstein would have found congenial or would have approved of. I am an example of precisely that. I think we ought to try to get a general theory of language. Wittgenstein thought such a theory was impossible. But at the same time, the work that I do builds on the type of work that Wittgenstein did. Specifically, Wittgenstein attacked the idea that we should think of “meaning” as the name of some introspected mental process, some mental process accompanying the use of words. I think his arguments against that conception are decisive, but now, having accepted his skeptical conclusion about the introspective mental account of meaning, how do we then give a general theory of meaning? And that is something I try to do, even though I think he would not have approved of it. If we are asking for names of specific philosophers who have been influenced by Wittgenstein, there are so many, one hardly knows where to start. But let me mention three. My colleague Barry Stroud, I think, is self-consciously influenced by Wittgenstein. Stanley Cavell is also very much, in important respects, a follower of Wittgenstein. And Richard Rorty, though again he did a lot of things I think Wittgenstein would have found uncongenial, nonetheless self-consciously saw himself as engaged in the type of philosophical enterprise that Wittgenstein was engaged in.

SC: It was Einstein’s longtime wish to complete a “theory of everything,” uniting the four fundamental forces of nature into one theory. Has there been a similar movement in philosophy, and if so, with what results?

JS: One of the commonest urges in philosophy is to try to get a general theory that will accommodate all philosophical problems using a unified conceptual apparatus and a common philosophical method. Many of the great metaphysicians held exactly this sort of conception of philosophy. One thinks of Aristotle, Kant, Leibniz, and Hegel as examples of precisely this sort of universalizing tendency. Philosophers in the Anglo-Saxon tradition have been less prone to try to get a theory of everything, but some of them indeed had such ambition, even though it was less grand than the great Continental metaphysicians. A famous example is David Hume, who wrote on a vast number of subjects and used a common empiricist methodology on all of them.

SC: Wittgenstein’s thoughts—and the field of philosophy in general—are quite complex for a layperson to grasp. You currently teach Philosophy of Mind and Philosophy of Society at Berkeley. How do you make these subject matters not only easy for students to understand, but also compelling?

JS. I do not try to make these subjects “easy for students to understand” nor “compelling.” On the contrary, I hope it is obvious to them that I am obsessed with these issues, and I try to explain to them as clearly as I can what the issues are and what are the possible solutions to the questions that have been posed. I think the subjects are so desperately important that it is not necessary to try to explain their importance. Questions such as the nature of the human mind and consciousness and how they relate to the rest of the world seem to me to be a natural thing for any intelligent person to care about, and I don’t have to convince my students of their importance. Similarly, the philosophy of society as I teach it, involves the basic structure, the basic ontology of the human social reality of money, property, government, marriage, universities, cocktail parties, etc. And again, I don’t think it is at all necessary to try to make these issues compelling. They simply are compelling as they are. I realize that some students are bored by the whole thing but then those people are not likely to want to take courses from me. I am struck by both the intelligence of my students and by their high level of motivation. One often hears how dreadful intellectual life is today and that the students today are supposed to have fallen away from the higher standards of the past, but that has not been my experience. The students I teach today are as good as any I have ever taught, and in many respects, they are even better.

Just about the worst thing we can do as teachers of philosophy—and I think Wittgenstein would have agreed with this—is to give our students the impression that they understand something when they really do not understand it. I would much rather my students went away thinking that there was a lot they did not understand than thinking they understood everything. Having said that, I wish to add that clarity is essential to good philosophy. My aim is not to make difficult problems seem easy, but to express difficult ideas clearly.