Direct realism

Direct realism is a theory of perception that claims that the senses provide us with direct awareness of the external world. In contrast, indirect realism and representationalism claim that we are directly aware only of internal representations of the external world.

Direct realists sometimes claim that indirect realists are confused about conventional idioms of perceptions. Perception is an exemplar of direct contact with something. Examples of indirect perception might be seeing something in a photograph, or hearing a recording of a voice. Direct realists often argue, contra representationalists, that the fact that one becomes aware of a tree in perception through a complex neurophysical process does not argue in favour of indirect perception. It merely establishes the method, undoubtedly complex, by which direct awareness of the world is secured. Arguing that perceiving a tree directly requires a magical, acausal mirroring of the tree in the mind is akin to arguing that traveling directly to grandmother's requires that one magically appear at her doorstep. The inference from the fact of a complex route to indirectness may be an instance of the genetic fallacy.

Direct realism proposes no physical theory of experience and does not identify experience with the quantum phenomena that are things in themselves or even with the twin retinal images. This lack of supervenience of experience on the physical world means that direct realism is not a physical theory.

Examples of the direct realist approach

Scottish philosopher Thomas Reid lived at the same time as David Hume. Reid argued strenuously against the notion that ideas, or sense-data, are the immediate objects of perception at all — he rejected representationalism.

One of Reid's arguments was very simple, and went like this: If representationalism is correct, then we are forced to either skepticism or phenomenalism. But skepticism and phenomenalism are both absurd; there surely is an external world, and we surely do have knowledge of it. So, by reductio ad absurdum, we must reject any theory that would force us to accept either skepticism or phenomenalism. So, we must reject representationalism.

What would it mean to reject representationalism? It would mean accepting that we do not perceive sense data at all. When I look at my hand, I do not immediately perceive a bundle or series of hand sense data which represent my actual hand. No, I immediately perceive my hand. I do not perceive any hand sense-data at all. So the view up for consideration now is that we immediately, directly perceive the external world.

This view is called direct realism, which Reid championed brilliantly:

Direct realism is the view that the immediate (direct) objects of perception are external objects, qualities, and events.

Do not confuse direct realism with the more naïve view discussed earlier, that the world is exactly as we perceive it to be. Obviously, sometimes we misperceive the world. The direct realist does not deny that there are perceptual illusions. The claim is, rather, simply that when we do perceive something, what we directly perceive, the immediate object of perception, is in the external world, not in the mind.

Nonetheless, the argument from illusion can be taken as an argument against direct realism because the argument from illusion shows the need to posit sense-data as the immediate objects of perception. How might direct realism answer the argument from illusion?

One strategy is to show how all those different cases of misperception, failed perception, and perceptual relativity — all those hard cases — do not really make it necessary to suppose that there are sense-data. Those cases might be explained without having to talk about sense-data.

Take first the case of the stick that looks bent in the water. Direct realism does not say that the stick actually is bent; it says, rather, that the stick, which is straight, can, in some unusual circumstances, look bent. And to say that it looks bent is just to say that the light, which is reflected from the stick, arrives at our eyes in a crooked pattern. So the stick can have more than one appearance. But the appearance of a stick isn't a sense-datum in my mind. It's a pattern of light, the sort of things that physicists can study, that arrives at my eye. What's mysterious about that? A similar sort of thing can be said about the bluish color of the hills in the distance. Hills, and everything else, can appear with all sorts of different colors; but the color is simply the wavelength of light as it reaches my eye. If the light from the green hills has to traverse many miles, then it may be bluish when it arrives at my eyes. There's no need to suppose I am seeing bluish sense-data: what I'm seeing is bluish light, which comes from the hills. The hills would reflect green light to my eyes if I were closer to them.

Now the case of pressing on my eyeball, and getting a double image. Well, it is undeniable that, when I cross my eyes and seem to see two fingers, there are two of something. But of what? Why say there are two sense-data? Why not, instead, say that I have two eyes, and each eye gives me a different view upon the world. Usually the eyes are focused in the same direction; but sometimes they are not. And as a result, each eye sees things in a different way. That does not mean that I see two visual sense-data in my mind; but it does mean that there are two slightly different acts of vision going on. One for each eye! What is mysterious about that? Nothing, as far as I can tell. And similar things can be said about the coin that appears both circular and oval-shaped: so the same coin can reflect different patterns of light to my eye. Does that mean that I perceive two different sense-data? No, all it means is that I perceive the same coin in two different ways.

Now as for Mary's vivid hallucination of the pink elephants. It was so vivid that the elephants were just as real as real elephants. We said this was evidence for thinking that she is perceiving sense-data; she is certainly not perceiving elephants, and yet she seems to be hallucinating something. So maybe it is elephant sense-data that she is hallucinating. Well, that seems like a pretty tough case to deal with. It definitely does seem that there is an object, in some sense, of Mary's hallucination; but this object is only in her mind. Isn't that what we'd call sense-data?

The direct realist might reply to that case as follows: Mary was not perceiving anything at all; she was hallucinating. That is a different, though related, mental process. So maybe Mary has visual images of some sort when she is hallucinating; that would not mean that she has such images when she engages in actual sense-perception.

This may not be a particularly strong reply. If there are visual images when we hallucinate, it seems reasonable to think that there are visual images when we see. It is the same way with dreams: if there are visual and auditory images of some sort in our minds, when we dream, it seems reasonable to think that there are visual and auditory images, or sense-data, when we are awake and perceiving things. We might ask for a better reply.

Some people end up denying that there are any such things as mental images at all, but this is rather hard to maintain, since we seem to be able to imagine all sorts of things: for example, here is something that will give you an image: imagine a square, then imagine the top of the square popping off and disappearing, and the two sides of the square collapsing together at a point, to make a triangle. Even if it should happen that perception does not involve images, other mental processes, like imagination, certainly seem to.

Mental images

The topic of mental images is very complicated and controversial.

One considered view is similar to Reid's. It is that, in some sense, we do indeed have images of various sorts in our minds when we perceive, and dream, and hallucinate, and use our imaginations, but when we actually perceive things, our sensory images, or sensations, if you will (that's Reid's word), cannot be considered the objects of perception, or attention, in any sense whatsoever. The only objects of perception are external objects. Even if perception is accompanied by images, or sensations, it is wrong to say we perceive sensations.

This conclusion shows that direct realism simply defines perception as perception of external objects where an 'external object' is allowed to be a photon in the eye but not an impulse in a nerve leading from the eye. Recent work in neuroscience suggests a shared ontology for perception, imagination and dreaming, with similar areas of brain being used for all of these. Based on this work, le Morvan (2004) argues that such a shared ontology is fatal for direct realism.

See also

• Philosophy of mind
• Consciousness
• Philosophy of perception
• Thomas Reid

External links

• Skepticism and the Veil of Perception, book defending direct realism.
• Pierre Le Morvan, "Arguments against direct realism and how to counter them", American Philosophical Quarterly 41, no. 3 (2004): 221-234. (pdf)
• Steven Lehar, "Gestalt Isomorphism" (2003), paper criticizing direct realism.
• A Direct Realist Account of Perceptual Awareness, dissertation on direct realism.
• "Sense Data", article from the Stanford Encyclopedia of Philosophy.
• Epistemological debate on PSYCHE-D mailing list
• A Cartoon Epistemology