Epistemology - Knowledge from Perception

What is realism?

Realism is the position that claims that we perceive physical objects directly and that there are physical objects that exist outside the mind and do not depend upon perception.

What is direct realism?

Direct realism is the claim that we perceive objects directly and all the properties of the object belong to the object itself, independent of the mind. According to direct realism, our perceptions are unmediated and as such there are only two things involved in perception: The perceiver and the perceived object.

Outline the argument from illusion against direct realism:

• The argument from illusion states that direct realism cannot be a valid description of how we perceive things, as sometimes objects can appear differently under certain circumstances.

• It states that there are occasions where you can perceive an object as one thing, when in fact it is another; such as how an oar appears crooked when semi-submerged despite being straight when removed from the water.

• These experiences give us a representation of the object that is not veridical, and are indistinguishable from the true form of an object unless you are already familiar with the illusion.

• Since these deceptive experiences cannot, by definition, be a true representation of the object, the conclusion is drawn that what we immediately perceive is not the true nature of the world, since what we are perceiving is not what is actually there.

How could a direct realist respond to the argument from illusion: 

• A direct realist may argue that in these situations the senses do reveal reality to us, we just occasionally misinterpret it when we make hasty generalisations.

• Normally we can understand that an oar appears crooked in water because of how light refracts in different mediums and we are not fooled by it, unless we make a rash judgement and misinterpret the information attained by our eyes.

• Additionally, it can be argued that just because something is misinterpreted, it does not mean that we are instead perceiving a separate appearance distinct from reality. A direct realist could reason that it is possible to perceive a straight oar as crooked without implying we directly perceive the crooked oar and then indirectly perceive the straight oar.

• So a direct realist may argue that we should instead say the oar “appears crooked”, rather than there “is a crooked oar appearance”.

What is the argument from perceptual variation against direct realism?

• The argument from perceptual variation is an objection meant to undermine direct realism.

• It states that ones perception of an object changes according to the positions it is perceived in, for example a ball may appear blue in the light but black in the shade.

• Since we know that the object itself must not change we also know that its properties are constant, as any change in the properties would cause a change in the object itself.

• If the properties are constant and our perceptions of reality were unmediated, the ball would appear the same in every condition.

• Therefore, since the object appears different we can deduce that our perceptions of the object and the object itself must be separate.

 

Explain Russell’s table example against direct realism: 

• Russell uses the example of a table to show that how we attempt to perceive objects appears to change based on our perception.

• He claims that we have habits of judging the “real” shapes of things using our brain, however we do this so unreflectingly that we believe we actually are seeing the real shape.

• For example, when we see a table at an angle, our brain evaluates the perspective and comes to the conclusion that we are seeing a square table, however we merely believe that we are seeing a square table directly, without acknowledging that we have constructed the real shape in our mind 

• The way the table looks also constantly changes as the conditions change (e.g. A table will appear darker if the lights are turned off, so what we see and feel is merely the “apparent” shape and texture, which we believe to be reality

How may a direct realist defend against the argument from perceptual variation?

• A direct realist may argue that there is no problem with accepting that an object appears to change, and there is no need to include an extra factor such as sense data 

• British philosopher Galen Strawman argues that there is a “real” colour, shape, taste, etc. These properties change when the conditions change, however under “optimum” conditions, the properties of the object would be the same for everyone who perceives the object in the same way. 

Outline the argument from hallucination against direct realism:

• The argument from hallucinations is an objection meant to undermine direct realism by raising the issue of hallucination.

• Hallucinations are cases when we perceive something that is not actually there. For example, an inebriated person may perceive a pink elephant, however once they become sober it is apparent that the elephant was merely a hallucination.

• If direct realism were true, then the elephant would have to exist in reality, however it does not.

• Therefore, it appears that direct realism cannot be true.

How might a direct realist respond to the argument from hallucinations?

• A direct realist may argue that hallucinations are a rare occurrence that most people do not have. We should, therefore, not concern ourselves with these. (Not a good counterargument due to refutation by counterexample (A theory can be disproved with a single counterexample))

• It may also be argued that we know the difference between hallucinations and veridical perception as we can rationally know that, for example, there is no such thing as a pink elephant, despite the visual evidence that suggests otherwise. 

Outline the time lag argument against direct realism:

• The time lag argument is an objection against direct realism that leverages the fact that it takes time (even incredibly small amounts) for light to reach our eyes. 

• In the time it takes for us to perceive the object it may have changed or not exist at all, as we only perceive a delayed impression of the object and its properties. 

• For example, some stars are billions of light years away, so the light takes very long times to reach our eyes. By the time we are capable of seeing the stars they most likely no longer exist. 

• Therefore, since we perceive a delayed impression of an object, we cannot truly perceive it directly.

How might a direct realist respond to the time lag argument? 

• The direct realist can argue that this response confuses what we perceive with how we perceive it.

• Yes, we perceive objects via light and sound waves and, yes, it takes time for these light and sound waves to travel through space.

• But what we are perceiving is still a mind-independent object (it’s not sense data or some other mind-dependent thing) – it’s just we are perceiving the object as it was moments ago rather than how it is now.

What is indirect realism?

• Indirect realism is a realist theory, meaning we