I must say this is a topic that's been bothering me for some time now, especially considering my confusion of current state of academic departments.

Put simply, I understand while reading philosophy of nature (the older term, I think, of nowadays physics) that the study of nature of the world (i.e. cosmology, parts of metaphysics, etc) used to lie in the philosophy department. But nowadays it seems as though philosophy stopped studying such subjects (or at least most of it, as subjects such as philosophy of mind still exists), and now the department that studies them is mostly physics.

Correct me if I'm wrong, but by that development, the conclusion to a student interested in (what used to be) "philosophy of nature", is that he should study physics, and not philosophy (perhaps some combination, but physics would be the dominant one). Is that conclusion the correct one?

Note that this is purely practical question.

[I had no idea which tag would fit, so edit if you have any suggestion.]


While looking at the answers a thought came into my mind - most of the answers say something like "you can't not do both, it'd be way less effective". If so, why there are so many physicists that don't study philosophy? Why, for example, are there no philosophy courses in the physics degree? Are they being ignorant of philosophy? Do they think physics is inherently enough? Or do they simply don't interact with philosophy to even know its necessity?

  • 1
    You are talking about Natural Philosophy. It was a precursor to Natural Science. So, yes, if you want to study that which was studied under "Natural Philosophy", then physics — or any other one of the natural sciences — is where place to go. Modern philosophy is not related to that which was Natural Philosophy. They are just named similar.
    – MichaelK
    Commented Apr 3, 2018 at 18:47
  • As scientific knowledge has expanded, it has tended to raise philosophical questions not previously mooted, and inform the debate over others. If these issues interest you, then having a working understanding of relevant scientific knowledge is a prerequisite.
    – sdenham
    Commented Apr 3, 2018 at 19:26
  • "Nature of the world" is a pretty high-minded term, taken at face value it is certainly beyond physics. I do not think one can avoid having a solid background in modern physics to credibly philosophize about it (thinking otherwise was, I believe, the cardinal mistake of "old" Naturphilosophie), but things like interpreting quantum field theory or speculating about string theory ontologies build on it as only a foundation. The term is philosophy of physics, and Princeton's Halvorson has a guide for those aspiring to engage in it
    – Conifold
    Commented Apr 3, 2018 at 19:52
  • I cannot see much point in deciding to study just one or the other, or not if you want a well-informed view. They are really two aspects of one study.
    – user20253
    Commented Apr 4, 2018 at 10:39
  • RE: Physicists studying philosophy, I suppose this is one reason the Physics department at UC Berkeley is in the College of Letters and Sciences, which has a large body of general-education requirements (philosophy classes satisfy some of them)... the Engineering school and the College of Chemistry have fewer such requirements, I think. Commented Apr 5, 2018 at 14:40

7 Answers 7


IMO, your conclusion is correct: If you are interested in a philosophical worldview based on science, in particular on physics, the best way is to take physics as major and philosophy as a minor. And do not restrict the subject to philosophy of science.

Without doing some pyhsics by yourself you will not be able to assess the weight of physical insights which are the subject of philosophical considerations.

But physics is a long and difficult study, it starts with mathematics, and there are no shortcuts on this way. Nevertheless the fruits are very rewarding. The study of physics brings you in contact with some of the greatest insights in the history of science.

Possibly you will enjoy on your way also some other scientific domains which contribute to a modern worldview, e.g. neuroscience.


Many philosophers of physics and quite a few theoretical physicists don't see a bright line between the two fields. Philosophers of physics often have at least an undergraduate degree in physics and regularly attend physics conferences; some also collaborate with theoretical physicists. Many physicists are hostile to philosophy, either because of a "shut up and calculate" attitude or because they're ignorant about philosophy. But other physicists enjoy engaging with philosophers.

For example, a friend of mine is a philosopher of cosmology. She's currently finishing up a postdoc that was jointly supervised by a philosopher of science and an astrophysicist. During her postdoc, she was trained how to take observations at a telescope in South America and wrote a few papers on dark matter with the astrophysicist and other members of his team.

From this perspective, you don't necessarily have to choose between physics and philosophy of physics. If you're putting together a reading list for your own personal edification, then feel free to read books and papers from both. If you're trying to choose an undergraduate degree, then double major (in North America) or look for a program of study that includes both physics and philosophy.

If you're trying to choose a graduate degree, the institutional difference is more important — career trajectories and opportunities can be very different. In that case, look for programs and particular advisors who regularly collaborate across the disciplinary divide and have a strong record of placing recent graduate students in the kind of academic career you're interested in. Reach out to them by email to get more information about the program, their current research interests, whether you might be a good fit, and so on.

  • I like this answer a lot as it pans out all the practical consequences. Thanks! Commented Apr 4, 2018 at 15:04

Physicists in general, have absolutely no interest in philosophy, or in doubting the foundations of how they know things. Even the philosophically inclined and capable like Einstein, generally fight for conservative positions rather than radical ones (look to Kuhn on why). Physics gets on with observations, experiments, and calculations.

Philosophy, including philosophy of science and philosophy of physics, is about something else. These do cover what we know about the world, and how we know it, and how we should do the practice of physics. Crucially, more generally it is also a space for asking questions which cannot be settled by observations, experiments, and calculations. Many physicists feel such questions are intrinsically meaningless, or at least irrelevant. But that is because they are using the tools that have resulted from a settled consensus on the answers to many questions they don't consider, answers which they take for granted.

In this age of dark matter and energy, of coming to recognise the huge challange of unifying the fundamental forces such as in addressing what time itself is, the foundations of physics have never needed questioning more. The current impasse is likely a result of the fact that the next places we need to go, are stranger than we can currently imagine. It will take more than just observations to get there.


My apologies for a longish answer to this somewhat important question that addresses one of the challenges that faces serious students of science and philosophy today.

Let us start from the beginning. The fields of science such as physics, chemistry, biology, etc. are specialized tools of human cognition. While there is some overlap in their domains of validity, it is not always clear how these domains ought to be defined, or whether it is even advantageous to draw hard inflexible boundaries between such fields of science. For example, there is some overlap between physics and chemistry, but it is arguably wiser to leave the boundary hazy so that both physics and chemistry can coexist and grow through a synergistic relationship. Also, the separation of domains between physics and chemistry is generally not considered a source of conflict because both physics and chemistry are fundamentally based on the same language of what is known as the scientific process, therefore the playing field is essentially the same, and the players think alike as they go about their specialized profession. In contrast, the gap between philosophy and physics (and science in general) has grown wider over the past centuries, as the great natural philosophers of the past remained in the past, and scientific progress continued to march forward fueling technological development on the basis of newer scientific theories which more and more were seen to rely less on a philosophical grounding, or at least so it seemed. Consequently, the important works of philosophers of science such as Karl Popper were largely ignored, because the subject of philosophy itself was no longer held in high esteem among modern scientists, being considered more a nuisance and an obstacle to scientific advancement rather than an enabler of novel scientific ideas. Philosophy had also lost the battle in the court of public opinion before the battle was even fought. How many philosophers of science have gained in the public limelight? How many philosophers of science have there been with tangible technological achievements to showcase? Philosophy was essentially relegated to the underground. Any prominent physicist who openly admitted to deriving inspiration from natural philosophy became a physicist who was taking a big risk of being ridiculed and ostracized. Who wants to commit professional suicide?

So how does this translate to the way physics is practiced and taught in academic departments? Once the ideological fault line was drawn between philosophy and physics, translating this reality to everyday academic life became self-evident. Physics departments in general are highly conservative in terms of their zealous adherence to the currently accepted tenets and theories of physics. The academic survival of the members of the department is typically contingent on their ability to attract research funding. Imagine submitting a research proposal titled “The philosophical foundations of quantum mechanics”. One such proposal in the wrong department is enough to ruin an academic career and jeopardize the reputation of the department, so over time it is not hard to see why an academic department begins to operate like a financially motivated self-perpetuating business. Many students of physics therefore learn by example to steer away from philosophical subjects.

So, how is a serious student of physics to study the wealth of knowledge accumulated in the field of natural philosophy without risking a career? Before addressing this challenge, it seems appropriate to keep in mind that both philosophy and physics have their unique utility, but that they are different in their methodological focus. Philosophy is entirely mental, with no objective tangible means of validating its ideas, while physics deals entirely in the physical realm of nature where theories can be subjected to experimental testing and validation, and subjected to the test of prediction. But can we do any physics without mental activity? Could there be any physical law without an underlying philosophical basis? It is unthinkable. Consider Newton’s famous three laws of motion. The great scientists of the past such as Newton were deeply inspired by what we nowadays call philosophy. Unfortunately, today’s new physics is losing touch with its philosophical foundations, but is this a wise direction to pursue? Ignoring the entirety of the philosophical method in the process of developing new theories of physics is like throwing the baby out with the bathwater, even though natural philosophy is really not the baby but more the mother of physics.

Therefore, as the rift between philosophy and physics continued to widen, and as physics continued to eclipse philosophy on the stage of tangible achievements, the guiding principles as well as the checks and balances traditionally derived from philosophy also faded gradually. Physics had conquered the opposition, and was free to advance theories that were exclusively based on experimental empiricism. It seemed sufficient to ensure that any accepted theory of physics agreed with experimental data, and made the correct predictions. In time, there was nobody there to question the validity of the extrapolations that were born from an unguided interpretation of the meaning of the theories of physics. In effect, physics theories began to invent new natural philosophy. The cart was put ahead of the horse, and it seemed to matter little that the cart and horse were in a state of collective confusion.

To answer the question, the perceived conflict between philosophy and physics appears to be a conflict between practitioners of science who are focused almost entirely in their own field of specialization, and therefore have little patience (or interest) in learning more about the philosophical method that they hardly hold in high regard. To them, philosophers “philosophize”, while physicists do the real hard work of theorization, computation and experimentation, which leaves little room or incentive for collaboration. True advancement and giant leaps in science (including physics) will likely come from those pioneering scientists who bucked the trend and have been able to derive practical knowledge from beyond the boundaries of science, and that includes natural philosophy. Those who have an inadequate foundation in the basic principles of nature, as elucidated in what was known as natural philosophy, run the risk of uttering nonsense and not know that what they are claiming is fantasy more than reality, while hiding behind the false comfort of the experimental validation of their theoretical models. It is seldom emphasized that all theories of physics (and science) are only mathematical models, and not to be misused to supersede the basic principles of physical reality. One such principle is causality. If one argues that something can happen from nothingness, who is to hold the person’s feet to the fire if all the philosophers have been silenced? Some of the interpretations that defy logic in today’s fundamental physics are simply illogical, and this is where natural philosophy could have provided the mental grounding through logic. If we stray too far in our flight of fantasy, who is to stop us if all the opposition has been silenced. Natural philosophy is a rich mental field from which to choose and pick the valuable plants that can be transplanted into science. Fundamental physics that is in stark contradiction to the basic principles of physical reality may well become a confused science barking up the wrong trees.

My opinion that I would share with serious students of physics (and science) who seek to advance human knowledge through the scientific process is: if you are studying to become a physicist, by all means study natural philosophy perhaps as a hobby in your own time, and if you are a philosopher then good luck to you with studying physics on your own time because learning the methods of physics requires persistent dedication, which explains partly why physicists and philosophers find it hard to communicate constructively because they hardly speak the same language. Like our scientific pioneers, including Newton and Einstein, we have a lot to learn from observing and reflecting on the workings of nature, and what better name to call it but natural philosophy?

  • “The philosophical foundations of quantum mechanics”..This is a paper that is long overdue. One example of how this might be approached is Ulrich Mohrhoff's 'The World According to Quantum Mechanics'. I find it astonishing that physicists usually have no inclination to wonder about this and just toss a coin for a world-view. It is also a sad comment on 'modern' philosophy that QM has had no discernible effect on the field. A quibble - Is it not the case that natural philosophy encompasses physics? . . . .
    – user20253
    Commented Apr 19, 2018 at 12:36

Regarding another comment from here, in many cases yes, physicists have absolutely no interest in philosophy, but that's not too relevant for the ones that do, like the author here, myself or many others. I'm a researcher with doctor's degree in physics and I like philosophy a lot, I even hold philosophy seminars. Generally speaking, when in physics you get to a halt given by an absurdity, it's best that you use logic and philosophy to be able to be out-of-the-box. Otherwise, you may be stuck in a no-solutions loop. You end up with theories supported by absurd math that have no practical application or value whatsoever.

The impasse in physics today is the result of false premise, and only doing textbook physics it's very unlikely that one realizes that. Philosophy can help and it did for many researchers, including my own teams. We were able to study physical aspects from a non-standard perspective and to come up with new valid theories, mathematically proved and experimentally confirmed, which contradict some theories widely accepted with the difference that the new ones can explain way more than the old ones.

From a difficulty perspective, studying physics is significantly harder than studying something like philosophy. Therefore, if you want to approach both aspects, it's safe to say that your will need to invest longer time in the study of physics.

Therefore, it would be good to do physics as official study while treating philosophy like a hobby, a way to relax. That's what I'd recommend after more than 20 years of activity in both fields.


Most historians of philosophy mark the beginning of science and philosophy at 585 BC when Thales of Miletus predicted an eclipse and claimed everything was made of water. From that point until about the 18th century, science was considered a branch of philosophy. ‘Natural philosophy,’ as you noted. Physics was the first area of research to formally break off from philosophy, and psychology was the most recent. Generally, when a branch of scientific research becomes sufficiently mature (or rather successful), it will break away from philosophy—or at least that is how the process is commonly described.

Thomas Kuhn describes science as being organized into paradigms. Paradigms allow researchers to assume a certain common framework and avoid fundamental arguments of a more metaphysical nature. In this description, the breaking-away process can be thought of as the result of the formation of a paradigm. Before the formation of a paradigm there is massive disagreement at the most fundamental levels; after the formation of a paradigm, the answers to basic questions have been assumed, and researchers are now focused on filling in the details (at which point they get their own department).


I'm a philosophy progressor at an R1 university, who majored in philosophy and mathematics, and considered going into pure mathematics instead of philosophy.

Other people have made great points that I won't repeat. But I will say that, in contrast to some of the above commentators, I doubt there's a simple way to gauge the relative difficulty of the subjects. It might be true that getting a BA in physics is harder on average than getting a BA in philosophy. But, then, getting into a top PhD program in physics is probably easier than getting into a top PhD program in philosophy, if only because philosophy programs are dramatically smaller, and physics jobs are much more plentiful. All told, my guess is that making original contributions to philosophy that might get you desirable academic job is considerably harder than making original contributions to physics that might do this. It might be wiser, then, to go into physics than into philosophy, other things being equal. (This is similar to the refrain that there are practically no jobs in logic, and many of those are philosophy departments. So, if you're doing pure math, you're advised to do a 'core' subject like algebraic geometry if you hope to get an academic job.)

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