I am not talking about miracles, religious revelation, or artistic expression, but something more mundane. There is a lot of "empirical" evidence that the Riemann hypothesis is true, the scare quotes indicate that the source of the evidence is "mathematical intuition". In psychology there are mental states that no one sees, touches, hears, smells or tastes, qualia with their perceptual fullness that can not be conceptualized or directly communicated, and abilities/skills "know how" with the same problem. In linguistics Kripke's theory of reference relies on "modal intuitions" to decide the truth of counterfactuals. But an empirical counterfactual is an oxymoron, especially when it is embedded into an entire "possible world".

Freudian psychoanalysis and Husserlian phenomenology are attempts to deal with some of them systematically, but they are traditionally confined to the fringe of science at best. The mainstream approach is empirical second hand, but behaviorism in psychology and linguistics, and nominalism in mathematics, were not very productive.

According to the naturalized epistemology there is no a priori "first philosophy" of science, methodology is subject to the "tribunal of experience" and revision, just as the science itself. Should it apply to non-empirical experience? Sense empiricism has served science well for centuries, and was fully embraced by Quine. Zammito takes him to task for it:

"Cognitive science is an empirical science working to unearth the mechanisms through which natural language constitutes itself. That account has had to recognize the indispensability of mental states, of beliefs, if it is ever to become adequate to the problem... There is still too much "first philosophy" in Quine. We must rescue naturalized epistemology from its own founder".

Note the use of "empirical" together with "mental states".

Questions: Does naturalized epistemology dictate that natural science should relax sense empiricism, and approach non-empirical phenomena partly first hand? If so, how can the scientific method be adapted to introspective/intuitive phenomena that are not readily reproducible, manipulable, measurable, and/or publicly accessible? What would play the selective role of empirical testing? Can there be non-empirical (more likely, not entirely empirical) natural science?

  • What ever do you mean by "naturalized" study of knowledge and "non-empirical phenomena"? The latter seems explicitic oxymoron. There is an epistemic limit to self-knowledge. It can be agreed when one states "I feel glad" or "my intuition tells me such and such" but there is no way for any other to empirically verify (read: know) these statements as corresponding to the case which they state.
    – MmmHmm
    Dec 10, 2016 at 1:20
  • Also, Scientific method is adapted to psychology yet the case remains that the conclusions from psychology are not confirmation of hypothesis and hence, psychology only "scientific" (a pseudo-science) in the same way all existing circles are only "circular" and not instantiations of all points two-dimensionally equidistant from a point (pace Euclid).
    – MmmHmm
    Dec 10, 2016 at 1:20
  • As to 'observable', as you ponder and analyze what you are impassively measuring, the process of your rumination is not 'observable' to anyone else. So it is not repeatable, etc, etc. The scientific method contradicts itself on so many levels that anything that falls outside its purview is the only place to search for 'certainty'.CMS
    – user37981
    Oct 4, 2019 at 22:09
  • Your question seems to ask about the exploration of consciousness, for which Mysticism or Yoga would be the usual name. Patanjali's Yoga is the general form of this and it is considered a 'non-empirical science' by its practitioners. The 'testing' you mention has to be conducted in our own experience so there is no communal method, but in other respects this meets Poppers' conditions for a science. This is not often a topic of discussion in mysticism since the idea of studying only the empirical data of our physical sense would never occur to anyone. . . . .
    – user20253
    Oct 5, 2019 at 11:40

4 Answers 4


You've mixed a number of unrelated things together as "non-empirical phenomena", and the answers are different for each one, much like the answers would be different for how law deals with "non-larceny".

When it comes to mathematical proofs, you start off knowing that you can't know empirically whether the Riemann hypothesis is true. So you can gather evidence about where it holds, and reason or experiment or analyze data based on that. But it's just science at that point--it's going the wrong way, in a sense, from a more reliable way to know things (in a very limited domain) to a less reliable one.

Qualia are phenomena that require some sort of explanation, just as our ability to see blue does. Science can use normal evidence-based approaches (e.g. Popperian falsification). It's worked reasonably well for neuroscience so far, though we know that we don't know anywhere near enough about the workings of brains to nail down what qualia are and how they are caused. So there isn't anything to see there--but you can certainly do empirical studies to verify that the phenomenon (that people report qualia) is true!

Counterfactuals are different yet again, having to do more with the relationship between models of reality and reality than any particular empirical study. It's not clear to me that the interesting cognitive science thing about counterfactuals is that they don't correspond to reality because nothing needs to correspond to reality in the brain (what is remarkable is that many things do!). And so it's not clear to me that there is even a phenomenon there that you're studying.

The bottom line, though, is that there is no particularly good reason, either from first principles or empirically, that you can build a robust base of knowledge on top of non-reproducible, non-quantifiable phenomena. Even if we adopt the most radical interpretation of Feyerabend's "anything goes" approach to the philosophy of science, it was "anything goes that works", and we haven't any indication that it works.

So while I am not sufficiently familiar with the tenets of naturalized epistemology to be sure about what they say, the answer from those fields where naturalized epistemology is supposed to draw inspiration is "no".

  • They are related by their source in introspection/intuition, which present the methodological challenge. For example, neuroscience is not in a position to link behavior or cognition to physiology directly, and intermediate description relies on "theories" of folk psychology. They "work", but taking them at face value worked badly for neuroscience in the last decade.ncbi.nlm.nih.gov/pubmed/24979469 It is they that have to be refined first, and that means dealing with introspection first hand. Anything does not go, but falsification does have to be diffused. The question is how?
    – Conifold
    Mar 8, 2016 at 1:53
  • @Conifold - When has abandoning falsification--or something logically equivalent to falsification but with a more convenient methodology--been a key step in understanding a tremendously complex process? (Also, I don't take that paper very seriously--they make a large number of rhetorical points without even strong argument to back them up in many cases, e.g. that intention does not have an onset.) In everything from climate modeling to prey capture, it has been precisely the detailed tests against data that have led the way forward. So the natural epistemologist should reject the premise.
    – Rex Kerr
    Mar 8, 2016 at 16:34
  • Oh--and I don't agree that the Riemann hypothesis is anything like the others unless you're doing meta-analysis: "when experts believe something is true, even if they can't prove it, it's probably true". Maybe? But now we're not studying the thing itself, but rather our attitude towards studied things for which there isn't yet a clear answer. I'm not sure there are any cases where studying the attitude, rather than the thing, can provide deep insight into the thing. (When attitude or impression is the thing under study, then it is different, of course!)
    – Rex Kerr
    Mar 8, 2016 at 16:37
  • Falsification is at best a moral ideal even in physics, but it especially doesn't apply to sciences with limited access and control (psychology, sociology, economics, linguistics). Nor does it address the key issue, generation of reasonable hypotheses, on that Popper absurdly agrees with Feyerabend. Design and interpretational errors in Libet-type experiments are widely acknowledged, as is their source, home grown ideas about mind ncbi.nlm.nih.gov/pubmed/20572769.
    – Conifold
    Mar 10, 2016 at 2:06
  • It's not that falsification isn't desirable if it can be had, but in vague settings, those involving introspection especially, shaping of hypotheses has to work with far less, so it better get more advice than anything goes. Popper's "idea" that we can only do science where falsification is available is what left neuroscientists stuck with folk psychology for hypotheses generator. Even psychoanalysis and phenomenology are an improvement on that. Another example of this effect is AI research, which embarrassingly had to turn to... Heidegger. leidlmair.at/doc/whyheideggerianaifailed.pdf
    – Conifold
    Mar 10, 2016 at 2:07

Empirical means an epistemological property of being of and/or derived from experience. Experience can be either the subjective (psychological states) or objective (experiment) kind, so non-empirical experience is an absurdity.

To answer according to the spirit rather the letter; do inaccessible phenomena fall into the domain of science? Yes, science can study the phenomena that are not immediately accessible, but it first needs tools to make them accessible. In the same way that the moons of Jupiter were not visible before inventing better telescopes, psychological representation is inaccessible to us lacking proper computational modeling.

Quine did not create a naturalized epistemology but rather forfeited it to empirical science, which I think is incompatible with empirical science. There is no way around proper epistemology, which can be scientific in the old sense but can't be reduced to the empirical.

If you are interested in epistemology I recommend you start with Leibniz and Kant, before reading Kuhn, Quine and Popper.

  • If you have references to sources that take a similar view this would give the reader a place to go for more information. Welcome. Oct 4, 2019 at 23:36
  • I think "empirical" in science is understood narrower than "derived from experience" broadly construed. More restricted to the five senses and discursive reasoning. After all, religious revelation or introspection are part of the "experience". The issue is with the type of access. Phenomenological or psychoanalytic data is "accessible" in the sense that people can learn the extraction techniques, should we count them as a "telescope"? The problem is reliability of the results, and what to do about phenomena not accessible in any other way.
    – Conifold
    Oct 5, 2019 at 8:48
  • @Conifold sure, techniques of communication can be thought of as tools to model psychological representation, how adequate the models they produce are is another question (you don't need perfect representation to start scientific research). It is trivial for philosophy how empirical is understood in science, as it is an epistemological term which like most is not used rigorously in common language, I use Kant's criterion of differentiation for a priori/a posteriori.
    – nathias
    Oct 5, 2019 at 12:42

Allow me to express a generally unpopular (but apropos) perspective...

As I see it, the entire centuries-long empiricist/rationalist divide boils down to an attempt to legislate the scope and definition of the word 'empirical'. Science and philosophy are meant to deal with an obvious tension between two obvious points:

  1. We cannot deny that someone has an 'experience' without undercutting the foundation of empirical research.
  2. We cannot accept that every 'experience' points to an extant phenomenon in the 'ontological' world.

Any way we look at this, 'experience' is a subjective event that occurs within the confines of our inner lives, and the analytical problem lies in relating or correlating that (inner) experience to other (inner) experiences — both in ourselves and in others — to produce a functional mapping that we can consider objective.

From this perspective, the idea that there are 'non-empirical phenomena' is a mere oxymoron. All phenomena are empirical by definition: even purely mental activities line thoughts, theories, dreams, and hallucinations are empirical experiences. The scientific/philosophical 'trick' lies in systematically sorting these experiences into two groups: those that help build a functional mapping of the 'objective' world and those that do not. In this sense, reasoning is as scientifically valid as measuring. Both reasoning and measuring take a subjective event (in the first case, the inward appearance of a putatively immaterial thought; in the second case inward appearance of a putatively material object) and subject those subjective events to a set of methods that are meant to be accessible to others so that the inward experiences can be validated.

The problem that has preoccupied the philosophy of science for far too long — as I mentioned above — is that people keep trying to legislate the definition of 'empirical' in order to avoid that moment of validation and the social and political frictions it causes. Certain fundamentalist groups deny the empirical foundation of certain sciences, because those groups have an experience of God that they refuse to question; certain hard-line skeptics draw an imaginary line through the center of human experience, demanding that experiences on one side of the line are 'real' while experiences on the other side are 'illusory'. But 'illusory' experiences do not seem illusory to those that have them, and subjective measurements are not wrong merely because they are subjective; willful ignorance swings into play, and both sides refuse to acknowledge the reality of the other's experience, which precludes the possibility of validation.

  • Why unpopular? It seems that the broadly Cartesian view you describe is the intuitive default. But we can roughly single out those experiences on which there tends to be broad agreement (roughly, coming from the five senses supplemented by reasoning), your "objective" group, and reserve the label of "empirical" for them. The rest can be called "phenomenal" or "experiential". If one is a realist though, they must admit existence of "objective" that is accessible phenomenally but not empirically (at least, for now), and decide how to go about it.
    – Conifold
    Oct 6, 2019 at 7:43
  • This view is unpopular with what I generally think of as the Skeptics Union: hard-line atheists and anti-theists, people who follow Popper or Russell, strong-arm proponents of medical science... a large cohort who take umbrage at anything they perceive as metaphysics, mysticism, religion, spirituality, etc. They generally see this line of reasoning as an opening for malefactors who want to question established science or push pseudoscience. Imagine how Dennett, Dawkins, or even Harris would respond to what I said, and you''ll see what I mean. Oct 6, 2019 at 13:55
  • As a side note, Helmuth Plessner held that the scientific is bound to "demonstrable" phenomena, i.e. those that have at least two modes of representation. E.g. mathematical and as a qualitative experience.
    – Philip Klöcking
    Oct 6, 2019 at 16:45

No one sees, touches, hears, smells or tastes an electron. Things do not need to be evident to be empirical, they just need to ultimately have notable effects. The main problem with all of these things is not that they are not empirical, it is that the environment in which they are observed has an agenda contrary to being understood. If you ask me whether I have imagined some aspect of a possible world, I can make myself believe that I have. That may or may not be true. But the limits of my imagination do shape my behavior, and on a large enough scale, that shape should be discernable.

We do not insist on removing intermediate states or placeholders that cannot be directly accessed from any other science, but we have tried to insist that they be removed from psychology and mathematics. (I continue to insist that mathematics is psychology.) We are allowed to talk about electrons, or fields, even though we can only detect them via devices whose construction presumes their existence. How then are qualia different. If we look at language, and we presume inaccessible formants, we are cheating. But if we look at gravity and we presume inaccessible formants, we are Newton.

To my mind, what there is here is not a problem, but a double standard, and it arises because we are too close to the problem. We have a very hard time with psychological models because they seem to either threaten or empower our personal existence on its own stated terms in a way that makes us defensive or uneasy. But that is just sentimentality that has to be moderated. We have to believe that if our model of qualia did not fit reality, we would actually describe it in a way that fit the public and not the private view. And we see that individuals have trouble with that.

But mathematics seems like a great example of psychological models, accessible only via introspection, that get adequately tested in a thoroughly public way. If our model of space is empirical, we can share geometry. If not, then not And that makes it empirical. It does not make it correct as physics, but it makes it empirical as psychology.

There somehow should not be a function that is everywhere continuous and nowhere differentiable, but we can agree that what we have intuited elsewhere means that this is not ruled out. We can trust our developed intuition over our more immediate intuition. So such sciences do work. They are just exceedingly slow going.

The answers are all "Do what people are already doing. The other sciences are not as different as we pretend."

Does naturalized epistemology dictate that natural science should relax sense empiricism, and approach non-empirical phenomena partly first hand? - It already does son, in the form of mathematics, and in experimental psychology and sociology.

If so, how can the scientific method be adapted to introspective/intuitive phenomena that are not readily reproducible, manipulable, measurable, and/or publicly accessible? - Volume and time. None of the other sciences use methods that are ultimately reproducible, etc. We make them appear so through statistical aggregation. Preserving the limited power of statistical methods, to make the most of limited volume, is already the approach experimental psychology takes. Sheer repetition and volume is the approach taken by mathematics.

What would play the selective role of empirical testing? Can there be non-empirical (more likely, not entirely empirical) natural science? Empirical testing should play the role of empirical testing. But we need to see things like the success of mathematics as an empirical fact. Ultimately discussion between humans is a form of empirical testing. We test maths by attracting interest and directly comparing internal mental models. Human discussion is full of empirical facts.

  • Repairing my stove the other day, I felt electrons!
    – J D
    Oct 5, 2019 at 17:28
  • @JD No, quite obviously you felt a qualia with several possible physical causes. You traced it to nerve disruption, potentially caused by excessive changes in charge, because of what you were doing. But you would feel that same effect from other causes, such as physically damaged nerves (I have diabetic neuropathies and I have been electrocuted a few times. They feel the same. I know.). So you did not really even feel electricity, much less electrons. Even our most empirical sciences just assign qualia meaning by attaching theory. This is not a special case, it is the general one.
    – user9166
    Oct 6, 2019 at 1:51
  • Well said, sir.
    – J D
    Oct 6, 2019 at 19:21

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