Naïve realism claims that the world is pretty much as common sense would have it. All objects are composed of matter, they occupy space, and have properties such as size, shape, texture, smell, taste and colour. These properties are usually perceived correctly. So, when we look at and touch things we see and feel those things directly, and so perceive them as they really are. Objects continue to obey the laws of physics and retain all their properties whether or not there is anyone present to observe them doing so.
It has been characterised as the unquestioned acceptance of the following 5 beliefs.
The debate over the nature of conscious experience is confounded by the deeper epistemological question of whether the world we see around us is the real world itself, or merely an internal perceptual copy of that world generated by neural processes in our brain. In other words this is the question of direct realism, also known as naive realism, as opposed to indirect realism, or representationalism.
Representationalism is the philosophical position that the world we see in conscious experience is not the real world itself, but merely a miniature virtual-reality replica of that world in an internal representation. Representationalism is also known (in psychology) as Indirect Perception, and (in philosophy) as Indirect Realism, or Epistemological Dualism.
Naïve realism is distinct from scientific realism. Scientific realism says the universe really contains just those properties which feature in a scientific description of it, and so does not contain properties like colour per se, but merely objects that reflect certain wavelengths owing to their microscopic surface texture. The naïve realist, on the other hand, would say that objects really do possess the colours we perceive them to have. An example of a scientific realist is John Locke, who held the world only contains the primary qualities that feature in a corpuscularian scientific account of the world (see corpuscular theory), and that other properties were entirely subjective, depending for their existence upon some perceiver who can observe the objects.
Of all the branches of human knowledge, philosophy might be expected to be the best inoculated against the naïve realist error, since the issue of the epistemology of conscious experience is a central focus of philosophy. However, modern philosophy is just as rife with naïve realists as are modern psychology and neuroscience. As in psychology there is a recurring pattern of the occasional visionary who points out the fallacy of the naïve view, interspersed with long periods of enthusiastic support for the latest naïve inspired view, although again the issue is generally not addressed directly but only peripherally, as it is hidden in the details of various theories.
Although this issue is not much discussed in contemporary psychology, it is an old debate that has resurfaced several times, but the continued failure to reach consensus on this issue continues to bedevil the debate on the functional role of conscious experience. The reason for the continued confusion is that both direct and indirect realism are frankly incredible, although each is incredible for different reasons.
Problems with Direct Realism: The direct realist view (Gibson 1972) is incredible because it suggests that we can have experience of objects out in the world directly, beyond the sensory surface, as if bypassing the chain of sensory processing. For example if light from this paper is transduced by your retina into a neural signal which is transmitted from your eye to your brain, then the very first aspect of the paper that you can possibly experience is the information at the retinal surface, or the perceptual representation that it stimulates in your brain. The physical paper itself lies beyond the sensory surface and therefore must be beyond your direct experience. But the perceptual experience of the page stubbornly appears out in the world itself instead of in your brain, in apparent violation of everything we know about the causal chain of vision. The difficulty with the concept of direct perception is most clearly seen when considering how an artificial vision system could be endowed with such external perception. Although a sensor may record an external quantity in an internal register or variable in a computer, from the internal perspective of the software running on that computer, only the internal value of that variable can be "seen", or can possibly influence the operation of that software. In exactly analogous manner the pattern of electrochemical activity that corresponds to our conscious experience can take a form that reflects the properties of external objects, but our consciousness is necessarily confined to the experience of those internal effigies of external objects, rather than of external objects themselves. Unless the principle of direct perception can be demonstrated in a simple artificial sensory system, this explanation remains as mysterious as the property of consciousness it is supposed to explain.
Problems with Indirect Realism: The indirect realist view is also incredible, for it suggests that the solid stable structure of the world that we perceive to surround us is merely a pattern of energy in the physical brain, i.e. that the world that appears to be external to our head is actually inside our head. This could only mean that the head we have come to know as our own is not our true physical head, but is merely a miniature perceptual copy of our head inside a perceptual copy of the world, all of which is completely contained within our true physical skull. Stated from the internal phenomenal perspective, out beyond the farthest things you can perceive in all directions, i.e. above the dome of the sky and below the earth under your feet, or beyond the walls, floor, and ceiling of the room you perceive around you, beyond those perceived surfaces is the inner surface of your true physical skull encompassing all that you perceive, and beyond that skull is an unimaginably immense external world, of which the world you see around you is merely a miniature virtual-reality replica. The external world and its phenomenal replica cannot be spatially superimposed, for one is inside your physical head, and the other is outside. Therefore the vivid spatial structure of this page that you perceive here in your hands is itself a pattern of activation within your physical brain, and the real paper of which it is a copy is out beyond your direct experience. Although this statement can only be true in a topological, rather than a strict topographical sense, this insight emphasizes the indisputable fact that no aspect of the external world can possibly appear in consciousness except by being represented explicitly in the brain. The existential vertigo occasioned by this concept of perception is so disorienting that only a handful of researchers have seriously entertained this notion or pursued its implications to its logical conclusion. (Kant 1781/1991, Koffka 1935, Köhler 1971 p. 125, Russell 1927 pp 137-143, Smythies 1989, 1994, Harrison 1989, Hoffman 1998)
The key to this problem of fitting a spacious world into our brains is to notice that our experience is a 'view' of a spacious world. Things are separated by angles relative to an observation point. The separation of things by angles at a point means that we do not have a sense of depth that operates in the same way as our sense of things being separated in horizontal and vertical directions. Our sense of depth is based upon cues rather than an actual experience of the space between things. As an example, the stars in a planetarium appear incredibly distant even though they are on the ceiling of a room and would appear just as distant if viewed through virtual reality goggles. Visual depth in particular is a set of inferences, not an actual experience of the space between things in a radial direction outward from the observation point. This means that the things that are the spacious world of experience could be as small as just a few cubic millimetres of brain tissue!
If there is anything to be learned from the long history of the epistemological debate, it is that the issue is by no means simple or trivial, and that whatever is ultimately determined to be the truth of epistemology, we can be sure that it will do considerable violence to our common-sense view of things. This however is nothing new in science, for many of the greatest discoveries of science seemed initially to be so incredible that it took decades or even centuries before they were generally accepted. But accepted they were, eventually, and the reason why they were accepted was not because they had become any less incredible. In science, irrefutable evidence triumphs over incredibility, and this is exactly what gives science the power to discover unexpected or incredible truth. Ultimately, therefore, the most convincing argument for epistemological dualism is the fact that its monistic alternatives have all been refuted on sound logical grounds, which leaves epistemological dualism as the only viable alternative. (Naive Realism in Contemporary Philosophy, see for a detailed account of academic philosophical debate)
This argument was "first offered in a more or less fully explicit form in Berkeley (1713)" It is also referred to as the problem of conflicting appearances (e.g. Myles Burnyeat's article Conflicting Appearances). The basic outline of the argument goes as follows:
[W]e should remember that the following considerations are also part of informed commonsense.
A. What we perceive is often dependent on our organs of perception and their condition. If we had compound eyes, as flies do, we would receive information about the visual world in a completely different form. If we had jaundice, things would look yellow. If we had other sense organs altogether, like infra-red detectors or echo-location devices, things might appear to us in ways which we can’t even imagine. (Let’s call this ‘perceptual variability’).
B. Even our current perceptual apparatus is obviously not infallible. We are all familiar with perceptual illusions of various sorts. A major sub-classification of such illusions relates to whether the sensory organs are malfunctioning (as in jaundice) or whether they habitually misrepresent objects to us even in full working order (e.g. the Muller-Lyer illusion). (Call these phenomena ‘perceptual illusions’).
C. Sometimes these perceptual illusions extend to cases where we think we perceive things which in fact aren’t there at all (rather than just misperceiving the properties of things which are there to be perceived). This is a more radical case of perceptual error than simple illusion. (Call it ‘hallucination’ or ‘perceptual delusion’).
The basic claim is that in cases of illusion or hallucination, the object that is immediately experienced or given has qualities that no public physical object in that situation has and so must be distinct from any such object. And in cases of perceptual relativity, since objects with different qualities are experienced from each of the different perspectives or under each of the relevant conditions, at most one of these various immediately experienced or given objects could be the physical object itself; it is then further argued that since there is no apparent experiential basis for regarding one out of any such set of related perceptual experiences as the one in which the relevant physical object is itself immediately experienced, the most reasonable conclusion is that the immediately experienced or given object is always distinct from the physical object. (Or, significantly more weakly, that there is no way to identify which, if any, of the immediately experienced objects is the physical object itself, so that the evidential force of the experience is in this respect the same in all cases, and it is epistemologically as though physical objects were never given, whether or not that is in fact the case.)
The naive realist theory of perception is not threatened by these facts [A,B & C] as they stand, for they are accommodated by that theory by virtue its very vagueness (or ‘open-texture’). The theory just isn’t specific or detailed enough to be refuted by the (actually very rare) occurrence of these cases.
The cogency of this argument has been challenged in a number of different ways, of which the most important are the following. First, it has been questioned whether there is any reason to suppose that in cases of these kinds there must be some object present that actually has the experienced qualities, which would then seemingly have to be something like a sense-datum. Why couldn't it be that the perceiver is simply in a state of seeming to experience such an object without any object actually being present? (See the discussion below of the adverbial theory.) Second, it has been argued that in cases of illusion and perceptual relativity at least, there is after all an object present, namely the relevant physical object, which is simply misperceived, for the most part in readily explainable ways. Why, it is asked, is there any need to suppose that an additional object is also involved? Third, the last part of the perceptual relativity version of the argument has been challenged, both (i) by questioning whether it is really true that there is no experiential difference between veridical and non-veridical perception; and (ii) by arguing that even if sense-data are experienced in non-veridical cases and even if the difference between veridical and non-veridical cases is, as claimed, experientially indiscernible, there is still no reason to think that sense-data are the immediate objects of experience in veridical cases. Fourth, various puzzling questions have been raised about the nature of sense-data: Do they exist through time or are they momentary? Can they exist when not being perceived? Are they public or private? Can they be themselves misperceived? Do they exist in minds or are they extra-mental, even if not physical? On the basis of the intractability of these questions, it has been argued that the conclusion of the argument from illusion is clearly unacceptable or even ultimately unintelligible, even in the absence of a clear diagnosis of exactly where and how it goes wrong.
The main aspects of that account that are cited in this connection are: (i) the fact that the character of the resulting experience and of the physical object that it seems to present can be altered in major ways by changes in the conditions of perception or the condition of the relevant sense-organs and the resulting neurophysiological processes, with no change in the external physical object (if any) that initiates this process and that may seem to be depicted by the experience that results; (ii) the related fact that any process that terminates with the same sensory and neural results will yield the same perceptual experience, no matter what the physical object (if any) that initiated the process may have been like; and (iii) the fact that the causal process that intervenes between the external object and the perceptual experience takes at least a small amount of time, so that the character of the experience reflects (at most) an earlier stage of that object rather than the one actually existing at that moment. In extreme cases, as in observations of astronomical objects, the external object may have ceased to exist long before the experience occurs. These facts are claimed to point inexorably to the conclusion that the direct or immediate object of such an experience, the object that is given, is an entity produced at the end of this causal process and is thus distinct from the physical object, if any, that initiates the process.
In the above argument from the scientific account of perception, it is difficult to resist the conclusion that there is a fundamental distinction between the external object, if any, that initiates the perceptual process and the perceptual experience that eventually results. This perceptual dualism thus raises inevitably the issue of how and even whether the object can be known on the basis of the experience. What can and has been resisted, by the adverbial theory in particular, is the idea that this dualism is a dualism of objects, with perceptual experience being a more direct experience of objects of a different sort, sense-data.
Perceptual dualism implies, both an act of awareness (or apprehension) and an object (the sense-datum) which that act apprehends or is an awareness of. The fundamental idea of the adverbial theory, in contrast, is that there is no need for such objects and the problems that they bring with them (such as whether they are physical or mental or somehow neither). Instead, it is suggested, merely the occurrence of a mental act or mental state with its own intrinsic character is enough to account for the character of immediate experience.
According to the adverbial theory, what happens when, for example, I immediately experience a silver elliptical shape (as when viewing a coin from an angle) is that I am in a certain specific state of sensing or sensory awareness or of being appeared to: I sense in a certain manner or am appeared to in a certain way, and it is that specific manner of sensing or way of being appeared to that accounts for the specific content of my immediate experience... The essential point here is that when I sense or am appeared to silver-elliptical-ly, there need be nothing more going on than that I am in a certain distinctive sort of experiential state. In particular, there need be no object or entity of any sort that is literally silver and elliptical — not in the material world, not in my mind, and not even in the realm (if there is such a realm) of things that are neither physical nor mental.
The sense-datum theory accounts more straightforwardly for the character of immediate experience. I experience a silver and elliptical shape because an object or entity that literally has that color and shape is directly before my mind. But both the nature of these entities and (as we will see further below) the way in which they are related to the mind are difficult to understand.
The adverbial theory, on the other hand, has the advantage of being metaphysically simpler and of avoiding difficult issues about the nature of sense-data. The problem with it is that we seem to have no real understanding of the nature of the states in question or of how exactly they account for the character of immediate experience.
Scientific realism in classical (i.e. pre-quantum) physics has remained compatible with the naive realism of everyday thinking on the whole; whereas it has proven impossible to find any consistent way to visualize the world underlying quantum theory in terms of our pictures in the everyday world. The general conclusion is that in quantum theory naive realism, although necessary at the level of observations, fails at the microscopic level.
[W]e have to give up the idea of [naive] realism to a far greater extent than most physicists believe today." (Anton Zeilinger)... By realism, he means the idea that objects have specific features and properties — that a ball is red, that a book contains the works of Shakespeare, or that an electron has a particular spin... for objects governed by the laws of quantum mechanics, like photons and electrons, it may make no sense to think of them as having well defined characteristics. Instead, what we see may depend on how we look."
Quantum mechanics is increasingly applied to larger and larger objects. Even a one-ton bar proposd to detect gravity waves must be analysed quantum mechanically. In cosmology, a wavefunction for the whole universe is written to study the Big Bang. It gets harder today to nonchalantly accept the realm in which the quantum rules apply as somehow not being physically real... "Quantum mechanics forces us to abandon naive realism". And leave it at that.
In the research paper The reality of virtual reality it is proposed that, virtuality is itself a bonafide mode of reality, and that "virtual reality" must be understood as "things, agents and events that exist in cyberspace". These proposals resolve the incoherences found in the ordinary uses of these terms... "virtual reality", though based on recent information technology, does not refer to mere technological equipment or purely mental entities, or to some fake environment as opposed to the real world, but that it is an ontological mode of existence which leads to an expansion of our ordinary world
The emergence of teleoperation and virtual environments has greatly increased interest in "synthetic experience", a mode of experience made possible by both these newer technologies and earlier ones, such as telecommunication and sensory prosthetics... understanding synthetic experience must begin by recognizing the fallacy of naive realism and with the recognition that the phenomenology of synthetic experience is continuous with that of ordinary experience.