Scientism schmientism! Why there are no other ways of knowing apart from science (broadly construed).

What is “scientism”? Most people who have heard of the term believe it’s something bad, an epistemic sin or affliction we should avoid at all costs. And that is indeed the most common usage of the term. The general gist is that of science overreaching, pushing beyond its proper limits, illegitimately colonizing other fields of inquiry. On the other hand, the word has also been appropriated by some people as a badge of honor, in defiance of its negative connotations. Philosophers like Alex Rosenberg and Don Ross now proudly proclaim to be advocates of “scientism”. Roughly, they believe that science should rule supreme in the realm of knowledge, and that there are no “other ways of knowing” apart from science.

This question of scientism and the limits of science was the topic of a volume I put together in 2018 together with Massimo Pigliucci. It contains contributions by both the friends and foes of scientism, and tries to answer the question: what, if any, are the proper limits of science? In Science Unlimited?, we distinguished two ways to go about defining “scientism”:

  • As a term of abuse similar to “pseudoscience” (pejorative definition). Here scientism is bad by definition, and the relevant question to ask then becomes: what qualifies as “scientism”? Is it a useful term? Is there anything in our modern society that fits the description?
  • As an ordinary philosophical position about the scope and purview of the sciences (neutral definition). The question then becomes: is this view defensible or not? Are there any good arguments in its favor?

Now yesterday I read a clever new paper in Metaphilosophy – yes, there really is a journal by that name – in defense of scientism, which follows the second strategy. The Finnish authors, known as the Helsinki Circle, present a neutral definition of “scientism”, distinguishing between four different flavors represented by the quadrant below. The four positions follow from two simple choices: either you adopt a narrow or a broad definition of science, and either you believe that science is the only valid source of knowledge or that it is simply the best one available.


Because “scientism” is mostly a bugbear defined by critics, most attention has been focused on the most radical version (upper left corner), which states that the natural sciences are the only valid form of knowledge. This is a pretty extreme view, which would imply that all of the humanities and social sciences are just rubbish. I believe this version of scientism is relatively easy to knock down, but in fact barely anyone holds it, with the notable exception of the philosopher Alex Rosenberg.

The authors want to draw attention to the other three versions of “scientism”, which are more defensible but nonetheless interesting and non-trivial. In the rest of the paper, they discuss how the different interpretations of scientism fare under two lines of criticism: (a) that scientism is self-defeating because the thesis itself cannot be demonstrated by scientific means; (b) that science inevitably relies on non-scientific sources of knowledge, such as metaphysical assumptions or data from our senses.

Foundationalist fallacy

Here I want to focus on the second objection. Does science “presuppose” the existence of an external world, or lawful regularities, or the truth of naturalism, or other metaphysical notions? No it doesn’t. These are merely working hypotheses that are being tested as we go along. I’ve argued for this position at length myself, in a paper with the neurologist Yon Fishman and earlier with my Ghent colleagues. As the authors write:

“One does not have to assume that science can achieve knowledge of the external world. Science can merely start with the hypothesis that some kind of knowledge could be achievable. For all practical purposes, this hypothesis would merely state that there are at least some regularities to be found. This hypothesis could be tested by simply attempting to obtain empirical knowledge with scientific means. If it is impossible to achieve this kind of knowledge, then the efforts would just be in vain. But hoping that something is the case is not the same as believing that it is the case.”

Second, does the fact that scientists rely on their sense organs invalidate scientism? No, because that’s a trivial point. It’s obviously true that science could not even get off the ground without sensory data, but this input too is being refined and corrected as we go along.

All these arguments about science being “based” on some extra-scientific assumption or source of knowledge are guilty of what I call the “foundationalist fallacy”. The mistake is to think that knowledge is something that needs to be “grounded” in some solid foundation, and that if this foundation is not completely secure, the whole edifice will collapse. But this metaphor is deeply misguided, and it inevitably leads to infinite regress. Whatever ultimate foundation you come up with, you can always ask the question: what is that foundation based on? It cannot be self-evident, floating in mid-air. This reminds one of the old Hindu cosmology according to which we live on a flat earth supported by four big elephants. Pretty solid, but what are the elephants standing on? On the back of a giant turtle. And that turtle? On the back of an even larger turtle. And so it’s turtles all the way down, ad infinitum.

Higgs-deeltje lijkt gevonden -
Large Hadron Collider at the European Organization for Nuclear Research (CERN) in Switzerland.

A better metaphor of human knowledge is that of a large web with many interconnected strands that mutually reinforce each other. The more connections, the more reliable our knowledge. The philosopher Susan Haack compares science to solving a crossword puzzle, in which vertical and horizontal answers intersect and strengthen one another. Naturally, if you want to solve such a puzzle, you have to start somewhere. But that doesn’t mean your first answer will be the “foundation” of all the others. In fact, you can start anywhere. If you’re smart, you start with a pencil first, filling in tentative answers, and then later when you’re more confident you use ink. If you’re stuck somewhere, you can always backtrack and erase some answers. As the authors write, knowledge is not an all-or-nothing, black-or-white affair, despite what the critics of scientism believe:

“Science is in the business of identifying and distinguishing practices, methods, experiments, instruments, forms of inference, and so forth that do and do not work. It emphasises and refines those that work while weeding out those that do not. In other words, even something with “very little epistemic quality” can be refined to become something of high epistemic quality. Hence, the “it’s all or nothing” reasoning that the critics of scientism so eagerly practise simply does not hold water”

Epistemic opportunism

My only concern with this paper is their notion of “epistemic opportunism” in science, which is the idea that science has no pre-established rules or methods but is open-ended and flexible, incorporating any method that proves reliable. I agree that science takes on board anything that works, but at a certain point this risks trivializing the thesis of “scientism”. Suppose that tomorrow we discover that reading tea leaves really worked, furnishing reliable predictions about future events. Scientists would definitely pay attention, and perhaps they would eventually be forced to incorporate tea leaves in their toolkit. But of course that would be a radical departure from science as we know it, and would lead to a complete overhaul of our scientific worldview. It would be lame to then say: “Scientism is still correct because reading tea leaves is now part of science!”

For me, an essential part of scientism is the belief in one unified, overarching web of knowledge, which was defended most famously by the philosopher Willard V.O. Quine. Take an everyday form of knowledge acquisition such as a plumber trying to locate a leak (I believe this analogy is due to the biologist Jerry Coyne). Now plumbing is not usually regarded as a “science”, but that doesn’t mean that my plumber is engaged in some “different way of knowing”. He’s also making observations, testing out different hypotheses, using logical inferences, and so on. The main difference is that he is working on a relatively mundane and isolated problem (my sink), which is both simple enough to solve on his own, and parochial enough not be of any interest to academic journals. Plumbing is not a science, but it is continuous with science, because it makes use of similar methods (observation and logical inference) and is connected with scientific knowledge, for example about fluid dynamics. The plumber or detective or car mechanic is not doing anything radically different from what the scientist is doing.

In my view, scientism is the thesis that holds: there are no other ways of knowing apart from those used by the sciences (broadly construed, including history and the humanities). All valid modes of knowing are connected to each other and rely on pretty much the same methods and modes of inference. If, on the other hand, we have a method that is completely detached from science and from the rest of knowledge, like personal intuition or revelation or reading tea leaves, we can be confident that it’s rubbish. As I put it in my chapter for the book:

“If a factual question is answerable at all, it can be answered using methods that are at least continuous with science. If some epistemic enterprise becomes too detached from science, and thus from the rest of the web of knowledge with which science is connected, that usually does not bode well for that enterprise (e.g. theology, analytic metaphysics, phenomenology).”

In any event, the defenders of “other ways of knowing” will have a hard time answering the arguments in this new paper!