1. Defending direct realism Hallucinations

2. We can identify when we are hallucinating Another sense can help us detect what is reality and what is a hallucination e.g. in hallucinations we can see things but we cannot touch them unlike real life. If we couldn’t detect hallucinations we would be unaware that they happened and the hallucination argument wouldn’t exist. Hallucinations

3. Hallucinations 2 We could completely deny that hallucinations are perceptions. Though they may be indistinguishable at the time for the hallucinator, that doesn’t necessarily mean that they aren’t a phenomenon of sorts. Immediate awareness can be different from reality and there is therefore no reason to conclude perception must involve immediate awareness of appearance as distinct from reality.

4. Direct realism criticism Time Lag argument

5. Time Lag Light from stars travels from such a distance that it take years for us to perceive it e.g. the supernova explosion or cosmic event Because it takes time for the light to reach us we cannot be sure if the source of it is still in existence. If it is not in existence we cannot be directly perceiving the image, and it must be an appearance. Similarly to star light, light in a closer range (e.g. from a table,) also takes time to reach us and so also cannot be a direct perception. Russell supports this point explaining that what we are perceiving is in fact sense data and the source may have come out of existence.

6. Defending direct realism Time Lag argument

7. Time Lag Direct realists must accept the science of time lag, but this does not have to mean that we don’t directly perceive things. Time lag explains that we perceive objects as they have been. Just because we do not perceive something instantaneously, it does not mean that we are not directly perceiving them, as we are aware of it as it was.

8. Direct realism critcism The Causal argument

9. Causal argument All physical things are made up of particles and atoms, which gave Locke a particular picture of the processes which underlie perception. There is a distance between us and the objects we perceive therefore there must be a process which connects our perception to the object. Boyle showed that sound cannot travel in a vacuum so therefore the air must function as a medium where the information from sound emitting objects travels to our ears.

10. Causal Argument There is an internal process where the information received is processess and these result in our perception. Particles convey information to the brain which produces a perception which represents the external world. What we are immediately aware of is not the external world itself, but an appearance of the world within our minds, indicating that we perceive the world indirectly.

11. Defending direct realism Causal argument

12. Causal Argument Defenders accept that I am aware of objects around me via a causal process but deny this implies that I am aware of the appearance of the object first and the real object only indirectly. Locke’s mistake is to think that if the processes leading to perception end in the brain, then there must be something such as an appearance, idea or sense in the brain. Reflection of experience appears to bear out direct realism. If Locke’s picture were correct, we would be aware of sense data as distinct from objects which cause them. We can see objects themselves, but we cannot distinguish them from the sense data. We are not aware of an appearance or an inference to the objects, but only of the objects themselves.