In dialog with others about philosophy, I have generally assumed that the basis of epistemology is a settled question – I. E. that the Locke/Russel/Popper approach, that our worldview is a hypothetico-deductive model of our external world fitted to our internal experience is pretty much universally accepted. This approach, which I have found is widely accepted among scientists is indirect realism. However, I have found that in discussing philosophy, that this is often not a shared assumption, and I would like to understand why.

Reading a discussion of representationalism: http://www.newworldencyclopedia.org/entry/Representationism, and the SEP article on epistemology https://plato.stanford.edu/entries/perception-episprob/ the major objection seems to be that indirect realism cannot ever give us certainty. But -- this is a question about the facts of our universe. Our WANTING certainty – is irrelevant. Worse, it is an explicit fallacy!

Both direct realism and idealism appear to be readily refuted by illusions, delusions, dreams and imaginings. This is noted early in the article, but only sporadically discussed in the following sections.

Several problems with representation are mentioned, but do not seem substantive. There is no infinite regress, as representation is an observed fact, not asserted as a necessary theory. And that matter is inferred not basic is – a problem for materialism, but again this is observation, and if a theory is in conflict with it – too bad for the theory. And neurophysiology has not challenged but STRENGTHENED the indirect point dramatically, by refuting the directness of all experience. For example – we see with a very narrow high resolution region, and our eyes unconsciously jitter to scan this high resolution region over our field of view. All “direct vision” is post-processing of this data in a memory buffer, informed by edge detection, color and tone clustering, object identification, moving object cueing, etc algorithms. IE basically NONE of what we see is “direct”!

So, what are the main objections to indirect realism?

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    What would a correct answer to this question look like? having some trouble figuring out how this is answerable here.
    – virmaior
    Commented Dec 5, 2018 at 5:12
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    I pictured four useful answers: 1) stronger critiques of indirect realism, and advocacy for direct realism, 2) an indication that indirect realism really has been fully accepted, contrary to my impression, 3) stronger critiques of indirect realism, and advocacy for idealism/phenomenalism, or 4) explanation for how some 4th option better addresses epistemology, and subsumes the other three.
    – Dcleve
    Commented Dec 5, 2018 at 5:19
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    Realism, direct or indirect, is a non-starter for many philosophers. The major objection is that there is no independent access, so the correspondence intuitions (beyond the pragmatics of science) end up being either incoherent or unintelligible. One does not even get to asking about certainty. Illusions, delusions, etc., are of no use, all major doctrines accomodate them. SEP reviews some standard counterarguments under Challenges to Metaphysical Realism.
    – Conifold
    Commented Dec 5, 2018 at 5:26
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    @Dcleve how would there then be one correct answer that addresses your question about philosophy? I think if you reworded it to "what is the main objection metaphysical realism?" it'd be more answerable.
    – virmaior
    Commented Dec 5, 2018 at 5:48

2 Answers 2


The main objection is that it is (or most forms of it are) incoherent, inconclusive, or ignorant regarding the difference and/or relation between causal/physical aspects of sensing and justificational/normative aspects of knowing which is central to indirect realism

I think most philosophical objections are not against "indirect realism" (e.g. scientific realism) per se, but against a certain understanding of the justificational basis of our knowledge, i.e. representationalism in the form of foundationalist or coherentist epistemologies (these SEP entries include an overview of ((counter-)counter-)objections as well).

The locus classicus when it comes to objections against representationalism in extreme forms (foundationalism/coherentism, internalism/externalism) and a call for a "middle way" (DeVries/Triplett 2000, Introduction, xxxii-xlii) is Wilfried Sellars' Empiricism and the Philosophy of Mind (EPM).

As you write, representations of physical objects are often thought to be an observed fact, i.e. facts are "given" in representations by perception - this is what Sellars attacks under the name of "The Myth of the Given". Knowing by sensing is in itself a complicated matter. It is impossible to discuss the whole depth and spectrum of arguments developed in this long and dense essay, but I can quote how Sellars exposes the basic problem at the heart of representationalist theories:

Now if we bear in mind that the point of the epistemological category of the given is, presumably, to explicate the idea that empirical knowledge rests on a ‘foundation’ of non-inferential knowledge of matter of fact, we may well experience a feeling of surprise on noting that according to sense—datum theorists [a brand of representationalism], it is particulars that are sensed. For what is known, even in non—inferential knowledge, is facts rather than particulars, items of the form something’s being thus-and- so or something’s standing in a certain relation to something else. It would seem, then, that the sensing of sense contents cannot constitute knowledge, inferential or non-inferential; and if so, we may well ask, what light does the concept of a sense datum throw on the ‘foundations of empirical knowledge"? The sense-datum theorist, it would seem, must choose between saying:

(a) It is particulars which are sensed. Sensing is not knowing. The existence of sense data does not logically imply the existence of knowledge, or

(b) Sensing is a form of knowing. It is facts rather than particulars which are sensed.

On alternative (a) the fact that a sense content was sensed would be a non-epistemic fact about the sense content. Yet it would be hasty to conclude that this alternative precludes any logical connection between the sensing of sense contents and the possession of non-inferential knowledge. For even if the sensing of sense contents did not logically imply the existence of non-inferential knowledge, the converse might well be true. Thus, the non-inferential knowledge of particular matter of fact might logically imply the existence of sense data (for example, seeing that a certain physical object is red might logically imply sensing a red sense content) even though the sensing of a red sense content were not itself a cognitive fact and did not imply the possession of non-inferential knowledge.

On the second alternative, (b), the sensing of sense contents would logically imply the existence of non-inferential knowledge for the simple reason that it would be this knowledge. But, once again, it would be facts rather than particulars which are sensed. (EPM, §3, bolded mine)

In other words: It is crucial how the story of how we become able to base veridical (and potentially fallible) observational knowledge of facts (cognitive, propositional, intentional, thus representations that are essentially normative and allow for justification within the "Space of Reasons") on the representations given by sense (nonpropositional, particular) is told if we are to maintain any form of empirical knowledge or realism.

The whole essay revolves around showing a) that the difference just described is a real and important one if we are to understand the epistemic authority of observational reports correctly and b) how different theories tell incoherent and fallacious stories that ignore or mingle the difference. And it gives a sketchy idea of how the alternative would have to look like.

For a good (the only?) clarifying commentary, see DeVries, W. A. & Triplett, T. (2000). Knowledge, Mind, and the Given: Reading Wilfrid Sellars's" Empiricism and the Philosophy of Mind," Including the Complete Text of Sellars's Essay. Hackett Publishing.

  • I have questions about this argument by Sellars. a) and b) above look like a false dichotomy, and complex questions. The Popperian approach is that we start with experiences, and "facts" are our most reliable/consistent speculative models that we build from those experiences. Our actual circumstance is c) "It is particulars which are sensed. Sensing is a form of knowing. Facts are inferred. Inference is a form of knowing. Basic reasoning is directly intuited. Direct intuition is a form of knowing."
    – Dcleve
    Commented Dec 5, 2018 at 23:16
  • @Dcleve: I guess any level of clarification will have to be the subject of a different question. I am serious when I say that without reading the commentary and perhaps an essay from Rebecca Kukla from the same year, it is almost impossible to fully grasp the arguments. Even the commentary itself says as much. The gist of the argument, though, is that for knowledge to have epistemic authority (and not be mere utterance like of parrots), the person has to be (potentially) able to justify by knowing the veridical conditions of the statement, hence intuitive knowing is mythical givenness.
    – Philip Klöcking
    Commented Dec 6, 2018 at 6:50
  • In other words: Sensing by itself cannot serve as justificational basis of knowledge since experience is only transformed through the process of language learning so that it involves propositional claims and to be knowledge I have to be aware of the standard conditions, i.e. able to assess whether it may be the case that my experience happens in unusual circumstances and thus mislead me. This makes any form of "directly intuited" unintelligible if it is not reflected that what is meant is indeed representations that are normative claims caused by, not inferred from, sense contents.
    – Philip Klöcking
    Commented Dec 6, 2018 at 7:06
  • I have not responded further, as i wanted to get more of an understanding of Sellars. I am now 14 pages into his essay, and 35 pages into the commentary book. Which is, of course not very far at all ... But I can already see my initial objection being vindicated. Sellars relies upon his unspecified definition of "knowledge", and "positive epistemic status", and both appear problematic to me. I consider that we can have non-propositional knowledge, and that epistic conclusions can be drawn from it. So -- his master argument against the given, misfires. At least for me.
    – Dcleve
    Commented Dec 12, 2018 at 3:40

A comment on fallacy

'Our WANTING certainty – is irrelevant. Worse, it is an explicit fallacy!' Wanting something can't be a fallacy; only an argument can be a fallacy. The wanting may derive from or be defended by a fallacy. That is another matter.

A standard objection

I offer first a standard criticism of indirect realism :

The causal processes of perception have traditionally been taken by upholders of what is now called indirect realism, and what used to be called representative realism, as one of the most serious objections to maintaining a direct realist theory of perception. Direct realists, in their turn, have traditionally pointed to the inferential nature of indirect realism as one of the most serious objections to that version of realism. For, as the name implies, according to an indirect realist no one can ever perceive external objects directly. An observer must rely, instead, on his ability to explain the order of his past perceptions, and predict the order of his present perceptions, as providing him with inferential evidence for the following claim: that the best hypothesis to account for the sequence of his perceptions is that these perceptions, though themselves only the awareness of mental images (sense data), have been caused by the existence of (directly unobservable) external objects. And the fact that an indirect realist has had to support his claim to know that external objects exist, by appealing to this inferential evidence, has traditionally been taken as a weak point in his position. (Andrew Ward, 'Direct and Indirect Realism', American Philosophical Quarterly, Vol. 13, No. 4 (Oct., 1976), pp. 287-294: 287.)

A separate objection

I also submit a quite different objection.

Our perceptions are the endpoint of physical and neurophysiological processes working on sensory inputs. Whether those perceptions represent anything real, let alone represent it as it is, strikes me as problematic. Indirect realism is still realism; it still involves some claim to veridicity. We have, so far as I can make out, no way of knowing what representational accuracy (if any) our perceptions have. I quite accept that if we experience the world we do so indirectly; that this experience is veridical, as the use of 'realism' ('indirect realism') implies, is an open question.


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