As is usual for my Great Debates threads, this has gotten rather more lengthy than intended; as a result, I’ve tried to break it down into different sub-headings for better legibility. That way, anybody who’s interested in the topic, but finds it a bit much to digest in one sitting, can maybe pick up where they left off another time, or perhaps skip some sections completely. If it’s still TLDR, well, I don’t think I can help that.
I. Introduction
I frequently encounter the notion—on this board, but also in the popular media/among other scientists—that philosophy is, in some sense, a thing of the past: that it has outlived its usefulness (if it is even admitted that it ever was useful in the first place), that it has been superseded by other methods of knowledge acquisition (typically, science), or that it’s really just all a vain pasttime of idle navel-gazers. The main proponents of such notions seem to be scientists, and most often, my fellow physicists: Steven Weinberg’s book Dreams of a Final Theory contained an entire chapter ‘Against Philosophy’, Stephen Hawking has been vocal about the “death of philosophy” (while calling himself a proponent of a—widely considered to be refuted—philosophy of science called ‘logical positivism’), Feynman was vocally anti-philosophy (calling philosophy of science ‘as useful to scientists as ornithology is to birds’—of course, one may debate if it’s the intent of philosophy of science to be of any use to scientists), and the list goes on.
Chief reasons for this alleged failure of philosophy seem to be that it doesn’t produce results, or at any rate, that science produces better results, that it’s arbitrary, and basically just word-mincing. Additionally, there is a widespread feeling of the irrelevancy of philosophical discourse, both for everyday life and for scientific endeavours.
In this post, I mainly want to examine the relation between science and philosophy, and in particular, whether it’s justified to claim that ‘science supersedes philosophical enquiry’; but first, a few words on philosophy’s relevance in the modern world. I must admit that I’m a bit flummoxed by those who claim that philosophy has no bearing on our everyday dealings—when I look around, I find that our world is absolutely steeped in philosophy: our political system is the result of hundreds of years of discourse, as are our judicial and educational systems. And they are what governs virtually everything we do, day in and day out: our education, influenced e.g. by Locke’s Some Thoughts concerning Education, or Rousseau’s Emile, largely dictates what we are capable of doing; the political system, which has, of course, been an object of philosophical discourse at least since Plato, shapes the society in which we are able to do it; and the judicial system, in the last century subject to prominent discussion by John Rawls and others, dictates if what we do is allowed or not (I’m obviously speaking very superficially on every count here). I can only imagine that, like the air we breathe, the philosophy that shapes our daily lives is simply so ubiquitous as to be nearly impossible to detect. In any case, I think the relevance of philosophy—or at least past philosophical discourse—to the shape of our day to day life should be without question.
II. The Relationship of Science and Philosophy
Now for something a little more meaty. Scientists often allege that their results show the obsolescence of philosophy, which has allegedly never produced anything comparable. I think this statement is wrong along several lines: first, I don’t believe that a naive comparison between scientific and philosophical results is appropriate, i.e. both disciplines aren’t necessarily after the same kind of insights, and scientists holding philosophical discourse to their (empirical and deductive-nomological) standard of ‘meaningfulness’ are simply committing a category error; second, I don’t think there is a strict separation between philosophy and science, in the sense that is alleged here; and third, I do believe that there are many examples of cases in which philosophical inquiry has been instrumental in scientific progress.
The first and second points concern the relation between science and philosophy, and thus, I’ll tackle them together. Basically, my position is that even in this day and age, scientific inquiry is still best seen as a subset of natural philosophy, so a subset of philosophy proper. The reasons for this are both historical and with regards to content. Historically, it is of course no great secret that science has developed out of philosophical inquiry into nature, starting at least with Aristotle. It’s sometimes said that philosophy is what’s done to a problem until it’s sufficiently sharp to become the object of a more specialized science. There’s something right with that, but it’s too one-sided, because what is ‘done to the problem’ by philosophy is at least in part the development of special tools with which to attack it, and it is these tools that then ultimately evolve into a specialized science.
For a metaphor, consider scientists as those that sit on the outer branches of an apple tree, where they’re naturally those able to get to the fruits best. Now, the prevailing attitude in science about philosophy is one of prasing the apples at the cost of the tree—essentially, that now that we can get at the apples, we’ve got no use for the tree anymore. Indeed, some sitting on those outermost branches seem to be just about ready to get out their saws…
As regards content, the question is: how do we differentiate between that which is a proper object of philosophy, and that which is an object of science? Those making the strongest claim in favour of science superseding philosophy typically allege that eventually, all philosophical content will be made the object of some science, leaving thus philosophy itself empty (or, in some cases, showing that it has always been empty). I don’t believe this is going to happen, at least not with the way we currently understand science (and those making the argument certainly do). The reason for this is a difference in kind in the contents of philosophy and science.
This is best seen, I think, using a ‘pseudo-historical’ reconstruction of how scientific inquiry might have developed from philosophical grounds. The reason I’m speaking counterfactually here is that in the real world, things are far more messy and less clear; nevertheless, I think a carefully examined fantasy can shed some light on these relationships.
First, we need to clarify what, exactly, we mean by ‘philosophical content’. This is, of course, an object of ongoing philosophical discourse itself, discourse which indeed has often been the cause for alleging philosophy’s impotence (philosophers can’t even get clear about what philosophy is!). I’ll suavely ignore all of that, and submit that it’s at least a useful fantasy to say that the central question of philosophy is ‘how should I live my life?’. It’s in the attempt to answer this question that at least a plausible story can be told about how philosophical discourse evolved: we are immediately presented with further questions, such as, ‘what is this thing called ‘life’?’ or, ‘what is this thing called ‘I’?’, ‘what tells me what I should or shouldn’t do?’, ‘what is the world I live in?’, ‘what can I know about that world?’, and so on. I think that most of the traditional arenas of inquiry of philosophy can be brought in relation with that question—moral philosophy and ethics attempts to tell us what we should and shouldn’t do, perhaps in relation to others, ontology concerns the question of what the world is made of, which must delimit what we can do within it, epistemology concerns the question of what we can know of the world, and so on.
But I think the most important aspect of that question is that we should not imagine it to have an objective answer. There is no one, uniquely right way to live your life. It is in this failure to have an objective answer that philosophy, and the aim of philosophical inquiry, differs from science: there can be no philosophical method in the sense that there is a scientific method, that is, there is no ‘royal road’ to philosophical truth. Philosophy thus can’t be, as science is, exhausted by the empirical, deductive-nomological method that just chips away at falsehood until what’s left is true; rather, it is mainly discoursive, because with every culture, with every society, answers to its key questions change, and in result to the discussion of these questions, cultural and societal changes are produced. It’s a reciprocal process: the environment changes the discussion, and the discussion changes the environment. Science, on the other hand, works from the assumption (itself of course philosophical!) that there is an empirical truth to discover, and thus, follows essentially an algorithm that ultimately converges on this truth, which is (again, assumed to be) independent of the context in which it is arrived at.
Philosophy is in some sense closer to textual analysis: Heidegger has proposed the notion of ‘hermeneutical circle’, in which the analysis of parts of the text change the reception of the whole, while the reception of the whole in turn influences the analysis of the parts. This is not a process of converging on capital-T ‘what did the author want to say’-Truth, but a continuing examination of the text in relation to its recipient, and of the recipient by virtue of their reception of the text. This is what has led to such at first cryptic (some would say, nonsensical) remarks as Derrida’s “there is nothing outside of the text”.
But this nonobjectiveness and ever-continuing dialogue does not make philosophy arbitrary. Both text and context, so to speak, at any point are definite, if fluent objects; and besides, as I have heard it expressed, “while philosophy is not itself empirical, it is bounded by the empirical”. And just for this reason, philosophy has given rise to science; but science, by its very constitution, will never usurp philosophy, which will continue as meaningful dialogue as long as there is (some version of) humanity trying to come to grips with its place in the universe.
III. Philosophy aiding Science
Finally, despite the claims of its detractors, there is ample historical precedent for philosophy being important to scientific discovery. I’ll just briefly note four relatively recent examples, three from my own speciality (quantum information theory), and one from the development of relativity theory. In order to not get too abstract, I’ll keep the discussion minimal; if anybody’s interested in hearing more, I’ll gladly elaborate.
First, quantum information theory basically starts with Bell’s theorem: in proving that classical theories as they are widely understood can’t account for quantum mechanical predictions, the door was opened to finding cases in which things become possible using quantum mechanics that aren’t possible using classical resources. A chief example is, for instance, perfectly secure cryptography.
This is a result that is of a classically philosophical form: it tells you, you can believe A, but then, you have to believe B; you can’t believe both A and not-B. Here, A is realism—roughly, the idea that everything you can observe always has a definite value independent of observation—and B is the existence of non-local influences. Now, the unique characteristic of this theorem is that it gives you an empirical criterion for its applicability to the real world, that is, it tells you that if you make one observation, then it’s applicable, and if you make another, then it’s not. This is a prime example of the empirical boundedness of philosophy. It turned out that it does, in fact, apply to the world—and thus, has become an object of scientific discourse (it was one of philosophical discourse independently of this empirical corroboration). Nowadays, its consequences are a prime research area.
The second example is likewise related to things you can do quantum-mechanically that you can’t do classically. The culprit here is David Deutsch, who wanted to find corroboration for a particular interpretation of quantum mechanics, the so-called ‘Many Worlds’-interpretation. In doing so, he was engaged in a philosophical inquiry: he wanted to know what, really, is behind the phenomena, how the world works deep down. Indeed, the interpretation of quantum mechanics is an important sub-field in the philosophy of science to this day. What he ultimately discovered was quantum computation (specifically, the first algorithm leading to a speed up above classical performance, known as the Deutsch-Josza algorithm). I need not tell anyone how big an area of research this has become.
For the third example, I want to submit Dieter Zeh’s work on decoherence. Now this is a bit of a hairy topic to introduce, but basically, it’s about how a definite value is brought about in the course of a measurement—a notorious philosophical problem in quantum mechanics known simply as the ‘measurement problem’. His works were dismissed by several journals as being ‘too philosophical’—and, I suppose, by extension either of no interest or contentless. Today, decoherence is one of the most important areas of quantummechanical research, mainly in order to bring quantum computing to maturity.
It’s examples like these that make me sad every time I see somebody dismissing a result as being ‘just philosophy’; even if you don’t have any interest in philosophy itself (which I can understand), you should realize that it’s often just those ‘philosophical’ results that have driven concrete applied science.
Finally, as an example of how the interpretation of a physical theory can bring about advances in the formulation of further theories, consider Hermann Minkowsky’s interpretation of special relativity as being about the causal structure of spacetime. Although today it is often seen as such, it is by no means evident that this is the ‘correct’ way to think about SR; alternatively, you could just as well postulate the existence of a Lorentz ether, meaning that spacetime is just a container filled with stuff that makes material objects behave in a certain way[sup]1[/sup]. But in doing away with this picture, Minkowski arguably enabled the development of Einstein’s next stroke of genius, general relativity, in which the very causal structure of spacetime now becomes dynamical—it is much harder to see how this could have come about under a Lorentzian interpretation.
I think this last example shows most clearly the importance of philosophical groundwork in physical theory—and, if you permit me some speculation, I think it’s no coincidence that the current ‘rut’ in fundamental physics ever since roughly the inception of the standard model in the 60s neatly coincides with the rise of the generation of ‘savages’ (according to Paul Feyerabend), the Feynmans and Weinbergs, who lacked the philosophical sophistication of their predecessors—Einstein, Bohr, Heisenberg, and so on. Indeed, if we consider the model of Kuhnian revolutions in science, it may well be the case that revolutions need a philosophical impetus, or at least some reexamination, while you can only do away with it during the periods of ‘normal science’. But that’s a topic for another thread.
Regarding my examples above, you may object that all of the protagonists were scientists, rather than philosophers; this is the case for two reasons: first of all, I’m a scientist myself, and thus, am more familiar with their biographies and contributions; and second, philosophy is not a label on a person, but on what that person does, and every one of those scientists were certainly engaging in philosophical inquiry in regard of their discoveries.
IV. Concluding Remarks
I’ve argued that the notion that philosophy is either irrelevant to or superseded by science is utterly wrongheaded: science is not, ultimately, after the same sorts of knowledge as philosophy, and furthermore, is properly considered as the (current) end-point of a chain of inquiry that starts from philosophical roots—it grew out of the tools philosophers developed to bound their inquiry into the natural world. Additionally, the idea that it’s useless to science is simply not borne out historically; rather, development of both disciplines has always been most fertile in an atmosphere of mutual dialogue, not of (misplaced) competition.
So then, why the widespread hostility against philosophy in the sciences? I think the main reason is that we all want to be able to, in a sense, survey, or comprehend the world; but all too often, this degenerates into mistaking our own horizon for its end. Thus, whenever somebody talks about something beyond that horizon, they must be talking nonsense. This, I find, is all too often the reason behind the flat out refusal to engage with certain topics, be they philosophy, modern art, or (even) science. Nobody can survey all of our increasingly complex world, but few are capable of admitting this. This results in an attitude that considers nonsense everything that another does that we aren’t able to understand. In our increasingly complex and pluralistic world, I think this is not just sad—since this outright denial closes us off to whole areas of the world full of their own wonders—but even dangerous.
Finally, a word to the philosophers: I’m not a philosopher myself, and in fact, have had little training in philosophy. I hope to not have mangled it too much in my (necessary) simplifications, but if you feel I did, I hope you’ll let me know.
[sup]1[/sup]Oh god, there’s footnotes, too? Well, just the one. Ironically, the Lorentzian interpretation is lately starting to come to the fore again, in order to come to grips with the problem of quantizing gravity. The idea is that gravity may be emergent from the right kind of medium, and that thus quanitizing gravity directly might be as wrong-headed as trying to quantize water waves in order to get at the microscopic description of water. This bolsters, rather than contradicts, my point: the right interpretation may determine what physical theory ultimately proves successful.
More seriously, there are certainly gray areas, but science tends to be characterized by empiricism and quantitative methods. I would argue that math itself is a legitimate science (and not a branch of philosophy) because it’s actually empirical within its own domain – a mathematical result is, generally speaking, either right or wrong, and you can write a paper about it and have someone either corroborate it or refute it. You can write a paper about a philosophical question and philosophers will debate it until the cows come home, much as I’ve debated philosophical matters on my front porch with old friends until the sun came up. Nothing was accomplished but we had a good time.
