Is it wrong to call the theory that explains all four fundamental forces/interactions a Theory of Everything in philosophy?

My views:

I think this is not a misnomer, at least not if you are both a physicalist and scientific realist; and I think this is why it was named this in the first place. If you accept physics describes reality and reality is composed of atoms and their interactions, then it is deduced that all that ever happened/happens is a result of these interactions. And Then you have that a Theory of the four forces must also be a Theory of Everything.

  • We don't have ToE. If we have then it is possible to simulate similar (but smaller) universe on the computer.
    – rus9384
    May 12, 2018 at 18:25
  • Yes, it would be hopelessly wrong. It would be a theory of the four fundamental forces - assuming there is such things as fundamental force. It seems more likely that these forces are not fundamental but that's another issue. .
    – user20253
    May 13, 2018 at 13:24
  • @PeterJ Why are these not fundamental?
    – BlowMaMind
    May 14, 2018 at 5:37
  • @rus9384 Yes, we don't have a ToE. I never claimed we had one.
    – BlowMaMind
    May 14, 2018 at 6:11
  • Well, this is how our laguage works. Everything is derived from context. When someone says you should clean everything, that clearly does not mean the same everything as in the case of ToE. And everything in philosophy is different from everything in ToE.
    – rus9384
    May 14, 2018 at 6:52

7 Answers 7


Welcome to words. We use words this way =)

Actually, what you hit on is a rather fundamental and interesting detail. Even in philosophy, we must define the "domain of discourse," which is that which can be discussed in the discussion. Informally, it defines what "everything" is for the purposes of talking about it.

In the case of the "Theory of Everything" in physics:

A theory of everything (ToE), final theory, ultimate theory, or master theory is a hypothetical single, all-encompassing, coherent theoretical framework of physics that fully explains and links together all physical aspects of the universe.

Given that the domain of discourse for physics is... well... physical aspects of the universe, their usage of the word "everything" is reasonable. Of course, it doesn't qualify as "everything" in other discussions. Even within physics, the ToE explicitly does not include the initial state of systems, merely the eternal rules governing it. But within the community it is well understood.

To hold physics to a stricter standard than that would be tricky. Consider, for example, the Tao, which could be loosely translated as the Chinese concept of "everything." The famous quote about the Tao is:

The Tao that can be expressed is not the eternal Tao.

Well that's a bugger. If you are discussing "everything" in a scope which includes the Chinese concept of the Tao, you actually can't express everything!

Beyond that, there's a pragmatic reality: the catchy terms are the ones that stick. The whole big deal about the ToE is that, right now, our standard model has a symmetry group of SU(3)xSU(2)xU(1), which is just... messsy, by physicist standards. A ToE would unify that into one group, and that is desirable by physicists (for whatever reasons they wish to state). However, "Theory unifying SU(3)xSU(2)xU(1) into a single simple symmetry group" just doesn't quite have the market appeal as "Theory of Everything." That's how marketing works.

On a related note, Philosophy's etymology comes from "the love of knowledge." However, I can guarantee you that there are philosophers out there that don't truly love knowledge. That's just how people are. Do we need to relabel them because "philosopher" is a misnomer for them?


Very simply put: no, it is not wrong to name such a theory "the theory of everything" provided that everything is defined materially, as you have suggested. Such a theory will be capable of unifying all branches of physical science the way that chemistry and biology are unified today.

However, if there are "things" that are not material, then YES: it's wrong to call that the theory of everything. Are integers "things"? Obligations? Neighbors?


Even if you are a physicalist+scientific realist, the "Theory of Everything" would arguably not be a theory of everything. If the ToE would explain everything, then it would also explain itself, it would not just be a theory about physical objects, but also include a theory about theories. In other words, it would be circular and justify itself (since there wouldn't be anything outside itself from which it could derive justification, truth and justification would be physical properties in some sense). If we don't trust a viciously circular theory of physics, the we'd require a ground outside of "everything", which implies the ToE cannot be really a theory of everything. A related concern is that the ToE in physics would still have to presuppose concepts that are not physical and that cannot be adequately explained and justified by a unification of the four forces, i.e. mathematics and logic. Physics applies, but does not give a foundation for math and logic, since the validity of these does not depend on physics at all. The Pythagorean theorem or the law of non-contradiction are valid independently of physics. Hence, even if we would have a ToE, we'd have to assume the truth of math and logic, which then would not be part of the ToE itself. Following this, if you are a really radical scientific realist, and would argue that whatever is needed and assumed in a natural scientific theory also is real and exists, you'd be committed to some form of Platonism, i.e. realism about the ideal entities of mathematics and logic (numbers, forms, etc.). That means your physicalism+scientific realism would commit you to the view that there are non-physical ideal entities ...


This "everything" refers to what? what is everything? Physics is everything? The mathematical model that shapes physics describes everything? Are colours "things" that are reduced to mathematical formulation? (all the qualities vs quantities). For example, in a Aristotelian perspective this is clearly a misnomer.

To be more precise, if in some time in future the string theory or another theory came in to being describing the four known forces this would just mean that we have a theory that describes that four forces. Are the four forces the only existent? Is the possible mathematical model a perfect description of all reality?

The collapse of the wave function in quantum theory is not something that is understood in the theory, you need to go outside the theory to explain, based in some metaphysical foundation.

  • Why should "colors" be an exception to the physical nature and mathematical describability of everything?
    – BlowMaMind
    May 14, 2018 at 6:09

It depends what the answer turns out to be. But consider the last time we thought we were 'nearly there' -

"There is nothing new to be discovered in physics now. All that remains is more and more precise measurement." - Lord Kelvin, around 1901

So, the year before the 'details' of: (1) the black body problem (2) Brownian motion (3) the photoelectric effect; turned out to require all of quantum mechanics. And dealing with the apparent absence of the assumed 'ether' required special relativity.

We have: dark energy and dark matter, the nature of singularities, the origins of the big bang, the nature of time, renormalisation problems in quantum mechanics, the fine tuning problem; among the ideas that pop into mind. It seems like hubris, to think none of these threads will unravel more than they sew up.

If QM & GR are unified in an 'uncomplicated' way, it would still only be a theory of 'everything' like atomic theory accounts for all of chemistry. That is, explanatory in principle not in practice. Many remaining theories of new phenomena will need to arise, and be attached to the tree of knowledge arising out of any TOE - and some of those branches will have to solve major outstanding ng problems like whether BQP = NP

On a practical level, given issues around computability, things may not be within the scope of explanation-prediction in practice from a TOE, within the constraint of the matter and energy in the universe. So, would be in seperate explanatory 'emergent layers' supervening onto the TOE reality.

Our own specific consciousnesses are the kind of thing which might evade such co putation limits. Because vast series' of unlikely events may be involved in getting to a specific outcome, there may still be limits on how much detail we simulate our own history with, and so a human in practice attached to such a chain of causation may evade in subtle ways predictions of that humany in theory, limiting explanation-prediction of this to probabalistic predictions, even in definite situations. Whether this is a limit on explaining 'everything' depends on how you define explanations. But I would suggest if you can't predict someone fully your understanding of them is in some sense incomplete.


It is not a "theory of everything" - that is a misnomer: This is an excellent question, since it raises some interesting questions about the nature and purpose of theory. I'm going to offer the contrary view to the OP, that the physical theory he described cannot properly be considered a "theory of everything". My argument appeals to the fact that such a theory would not be sufficient for human use; it would not obviate the epistemological need for other theories that are not derived from that theory. My argument for this is below.

If I understand correctly, what you are describing is a physical theory that correctly encapsulates the motions and interactions of all physical things, which under your assumption of physicalism, is all things. (Whether this theory ends up being four fundamental forces, or twenty, or one, is really beside the point.) For the sake of argument, I will accept your interpretive philosophical premises of physicalism and scientific realism. Even with this interpretation, there are some problems with the view that this theory constitutes a "theory of everything".

The purpose of "theory" is to provide an aid to understanding and predicting the state-of-the-world; a "theory" is an epistemological tool to assist in the acquisition of knowledge. From this purpose, a theory could legitimately be said to be a "theory of everything" if it obviates the need for any other theory (other than theories derived from the theory of everything). If there is a need for other theory that is not derived from the "theory of everything" then this must mean that the purported "theory of everything" needs to be supplemented, and hence, does not adequately describe everything. Note that this is an epistemological standard, not a metaphysical one; even if a "theory of everything" is metaphysically sufficient to determine the state-of-the-world, it does not necessarily follow that it is epistemologically sufficient for use in acquiring knowledge.

Problem 1 (Laws of interaction are not sufficient to obtain states-of-the-world): A theory that correctly prescribes the motions and interactions of all things is not sufficient to determine the state-of-the-world at any given time. In addition to the theory of motion and interaction, you would also need a full specification of the world at a single point in time, and this is absent from the theory. (The theory gives the equations for change, but you also need a starting point.) It is possible that your theory prescribes some form of uncertainty principle, such that the theory itself specifies that it is impossible for an observer to measure the full state-of-the-world at a given time. Even in the absence of theoretical impossibility, it is practically impossible that this knowledge could be acquired, and so the purported "theory of everything" could not be used to acquire full knowledge of the state-of-the-world.

Problem 2 (Computation is impracticable - other macroscopic theories are needed): Setting aside the previous objection, suppose we are in a situation where we know enough about some aspect of the state-of-the-world that the "theory of everything" logically implies a later state. Even in this case, computation using the theory is an activity that is itself a change of states of things in reality, and hence, there will be cases where it is computationally impossible ---or at least impractical--- to obtain useful predictions of things that are logically implied by the theory. Imagine, for example, attempting to use a (correctly specified) physical theory of atoms to predict interest rates in the economy. The macroscopic variable of interest rate is so far removed from the microscopic components of the theory that there is a huge computational problem separating them. (Interest rates are determined by people's time-preference and transactions, which are physically determined by a huge complex web of physical bodies and surrounding environment.) In such a case, it would not be possible to apply the purported "theory of everything" to make predictions about the interest rate. Supplementary theory (e.g., standard economic theory) would need to be deployed instead.

  • I can't figure out if either of you is talking about the Standard Model + Quantum Gravity or something more ambitious, like string theory, which is usually called "theory of everything". I am also not sure why practicality should concern a physicalist, who, ironically, avails a user of ToE of God's resources, or at least Laplace's demon's.
    – Conifold
    May 15, 2018 at 4:13
  • The particular model that forms the claimed "theory of everything" is not really the issue here - the issue is whether or not a model that fully encapsulates the motions and interactions of all things constitutes a "theory of everything". Also, why would practicality (i.e., the ability to implement ideas in practice) not concern a physicalist? Do physicalists never apply theories in practice?
    – Ben
    May 15, 2018 at 5:10
  • "Motions and interactions of all things" already limits the form of ToE, it may include neither objects nor motions nor interactions in the basic ontology, let alone those with properties used in your reasoning, so whether a model "fully encapsulates" does depend on the type of model. What physicalists do in practice is moot, in their philosophy they are only concerned with what is possible "in principle". Since you accepted their position for the sake of the argument you are stuck with that too.
    – Conifold
    May 15, 2018 at 5:23

I think that the Theory of Everything term is too open to interpretation. It has some similarity to previous "universal philosophy" theories or isms, which claim or desire to formulate something that "explains everything".

The way I interpret this is that humans (at least some) have a desire to "complete everything". Since with all these problems, wouldn't it be nicer it there was a theory that "explains everything"? If you read the internet then you would notice that some people want to rely on chaos theory or Gödel's incompleteness theory or whatever to "explain pretty much everything". So that would support the view that some people desire consistency and non-fuzziness.

However, in the physics context of ToE. The ToE in fact doesn't even propose to be what the name says. It doesn't try and possibly will not explain all physics. What it tries and could do is "uniformize" existing theory into something that's more complete in the same sense as mathematics. That is, that it's logically consistent, even when one jumps to different levels. It could be a start for something bigger.

Instead of ToE they could perhaps use the term "uniformization theory". and perhaps label it further like "X's uniformization theory".

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