Against Fundamentalism

Abstract

In this essay, I argue that the idea that there is a most fundamental discipline, or level of reality, is mistaken. My argument is a result of my experiences with the “science wars”, a debate that raged between scientists and sociologists in the 1990s over whether science can lay claim to objective truth. These debates shook my faith in physicalism, i.e. the idea that everything boils down to physics. I outline a theory of knowledge that I first proposed in my 2015 FQXi essay on which knowledge has the structure of a scale-free network. In this theory, although some disciplines are in a sense “more fundamental” than others, we never get to a “most fundamental” discipline. Instead, we get hubs of knowledge that have equal importance. This structure can explain why many physicists believe that physics is fundamental, while some sociologists believe that sociology is fundamental. This updated version of the essay includes an appendix with my responses to the discussion of this essay on the FQXi website.

5 Responses to Online Discussion

Since it was posted on the FQXi wesbite, this essay has generated an interesting online discussion. Unfortunately, I was not able to participate actively in the discussion at the time, so I respond to some of the more interesting comments here. There is not space to address every comment, so interested readers are encouraged to read the full discussion online [14].

Jochen Szangolies argues that the reliable convergence of ideas in physics should be taken as evidence that physics is objective and fundamental, citing the historical example of the convergence of measurements of the charge to mass ratio of the electron. However, an advocate of sociologism could equally argue that sociological factors are responsible for the convergence. There would be sociological pressure to come up with a unique theory. Discussions of which methods of approximation are appropriate, which systematic errors to take into account, which methods of measurement are most accurate, and which methods of data analysis to use, all occur within the scientific community. These are primarily responsible for convergence, and could be affected by sociological factors. Of course, I do not personally believe that sociological factors are primary in this process, but convergence of ideas in physics is not the knockdown argument against sociologism that it might appear to be.

Szangolies also argues that there is some ambiguity over what constitutes a “node” and what constitutes an “edge” in the knowledge network. He cites the example that if “Socrates is a man” and “Socrates is mortal” are nodes, then the derivation of the latter from the former is connected by the edge “All men are mortal”, which could also be construed as an item of knowledge, and hence a node. Note that we could look at this example differently, viewing all three items as nodes, and the rules of categorical syllogism as the connecting edge, but then perhaps these rules should themselves be a knowledge node.

I was deliberately vague about what should constitute a node and what should constitute an edge in the essay, precisely because of this sort of ambiguity. The network can be constructed at various levels of coarse-graining, depending on what we want to regard as the units of knowledge, e.g. scientific papers, entire theories, basic facts, etc. However, scale-free networks are self-similar, which means that the coarse-graining of such a network would also be scale-free, so to a large degree it should not matter exactly how we construct it. It is also important to realize that the knowledge network is only a model for the structure of knowledge, that I hope caputes important features of that structure, but cannot be expected to capture all subtleties. In this sense, it is like a model in physics, where carefully chosen approximations are made in order to yield a useful explanatory theory because working directly with the fundamental equations would be too complicated. I am open to the idea that a more general discrete combinatorial structure might better represent the structure of knowledge, e.g. a hypergraph in which more than two nodes can be linked by a hyperedge. The only important thing is that we can define a notion of scale-free for that structure and that a network can be used to approximate it. The network structure of the scientific citation network, the world wide web, and Wikipedia are meant to serve as evidence that knowledge can be approximately represented this way, but I freely admit that there are subtleties in the structure of knowledge that are not fully captured by these models.

Szangolies also points out that my knowledge network is epistemic, and does not deal with the ontic structure of the world, i.e. what is really out there. I acknowledge that this criticism is appropriate from a scientific realist point of view, but I adhere much more closely to a pragmatist theory of truth, in which what is true rougly corresponds to what is “useful”. This means I view my epistemic account of knowledge as more fundamental than any ontic account, and am skeptical about the meaning of the latter. I am committed to a naturalist metaphysics, in the sense that I think we must look at how the things we call knowledge are actually acquired, rather than positing an a priori structure that they must fit into.

John C. Hodges points out that human societies have often adopted similar social structures, and that Darwinian natural selection may be responsible for this. A scale-free network is an efficient way of encoding knowledge, and I agree that once evolution has produced an intelligent social species, there would be Darwinian pressure to structure society in this way. So I expect alien species to structure their knowledge in a scale-free network, but this still leaves open the question of whether there is more than one local minimum for the structure of a knowledge network representing our universe.

Ken Wharton argues that the structure of a knowledge network can still be used to assert that physics is fundamental, in the sense that, as a hub node, it is more fundamental than non-hub nodes. Indeed, I recognize that the question of “more fundamental” makes sense. What I reject is the notion of “most fundamental” and the idea, common among physicists, that physics has the special status of being more fundamental than anything else.

Cristinel Stoica posits the idea that, since the world is fundamentally quantum mechanical, the knowledge network should be viewed as emergent from a unitarily evolving quantum state of the universe. Since I am not a straightforward realist about our scientific theories, I strongly reject this idea. The structure of the knowledge network determines in part the structure of our scientific theories, so I would say that quantum states are emergent from the network rather than the other way round.

Alyssa Ney points out the similarity between my view of knowledge and that posted by Quine in his essay, “Two Dogmas of Empiricism” [15]. Indeed, Quine is a major influence on my thinking, and I thank Ney for giving me a reason to reread this essay. Quine writes:

The totality of our so-called knowledge or beliefs, from the most casual matters of geography and history to the profoundest laws of atomic physics or even of pure mathematics and logic, is a man-made fabric which impinges on experience only along the edges. Or, to change the figure, total science is like a field of force whose boundary conditions are experience.

— W. V. Quine [15].

This is quite similar to my view of the importance of realizing that knowledge is constructed by societies and the role of experience at the edges of our knowledge network.

Ney also questions whether physicalism is in conflict with the strong program in the sociology of science. She argues that even if we have sociological explanations for the uptake of physical theories over time, this does not rule out the idea that there is also a more fundamental physical explanation for why they are true.

While this is true of the formal definition of the strong program, in which the use of the truth of a scientific theory as an explanation for its acceptance is rejected as a methodological principle, I believe that most advocates of this program are (at least covertly) social constructivists. Indeed, if you find sociological reasons for the uptake of physical theories everywhere you look then it becomes difficult to believe that any other explanation for their success is needed, and a descent into sociologism is likely, if not inevitable. Even rejecting sociologism, from my point of view, which is more pragmatist rather than realist, I find it difficult to understand what a “physical explanation” would actually mean in this context. Once I have explained why the theory is a useful addition to the knowledge network, in the sense of enabling an efficient encoding of experience in a scale-free way, I do not see what else is left to explain. I acknowledge that this account is not complete according to scientific realism, but debating the relative merits or realism and pragmatism will have to wait for a future essay contest.