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be allowed that predictions do not have to be strictly deductive consequences. It is enough
that they fit the model well.
Remark 1: Argument 4 captures, I think, all the virtues of argument 3, except that it is
clearer that prediction is central to the purpose of science in its pursuit of knowledge.
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Creationism
Remark 2: In order to successfully apply Argument 4, we need to argue that Darwin s theory
of evolution has made successful predictions. Here I would appeal to the example of protein
homologies as a prime example.
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Vision
The Psychology of Vision
Last modified on Monday, October 19, 1998, by Malcolm R. Forster
The Astonishing Hypothesis
That consciousness is nothing more than a "bunch of neurons firing in the brain"
Three reason for surprise
a. Reluctant to accept that a complex system can be explained by the behavior of its parts
and the interactions between them.
b. How can you reduce something subjective, like our vivid experiences of red , to
something objective, like neural firings? Support: Does not rule out the existence of
neural correlates.
c. How can the reductionist thesis explain the existence of free will? Answer: Our free will
may only appear to be free.
Questions Arising from the Psychology of Vision
A Metaphysical Question
1. Is consciousness anything more than a "bunch of neurons firing in the brain"?
Support for the astonishing hypothesis:
a. Reductionism cannot work; ignores that reduction is a dynamic interactive process.
b. Consciousness as a substance is a category mistake. Gilbert Ryle (1900-1976) and the
ghost in the machine. E.g., "N. G. gives me the creeps" does not imply the existence of
the creeps. "Which building is the university" does not wrongly imply that the university
exists, but it does make a mistake about the kind of category to which universities
belong. "It has crossed my mind" does is not mistaken about the existence of minds,
but does suggest that minds are in the same category as material things, though
different in kind (dualism). Hence arises the mind-body problems concerning how these
two substances interact, how do they exchange energy, and so on. Ryle thought that
dualism arises from a category mistake, similar to the mistake of thinking that there is
such a thing as the creeps that N. G. gives me.
Philosophical Questions about the Science
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Vision
1. Can the study of consciousness be reduced to neurophysiology?
2. How can one study consciousness in a scientific manner?
3. Does the fact that neurophysiological experiments are done only on anesthetized
animals limit the scientific study of consciousness?
4. Can consciousness be studied by introspection? Too subjective? Not testable, or
falsifiable?
5. Or is the use of some introspective evidence unavoidable?
6. Is there a theory in this science? Are there hard core assumptions in Lakatos s sense?
Philosophy of Science Questions that might be answered by the Science
1. What is observation?
2. Is observation theory-laden?
3. Is observation always a reliable source of information?
4. Is observation objective? Or are there biases that can be built into the observation? (Do
we see what we expect to see?)
Scientific Questions
1. Experiments show how different pieces of information are fed into the visual system.
But how are these piece put together again to produce a single visual experience, or
perception?
Ï% Is there an analogy between the way that information is processed in science and the
way that information is processed by the visual system?
Seeing is Believing?
Popular Misconceptions about Seeing:
1. Why should we study something so effortless?
2. We want to cure something when it s not working, but very few scientists bother asking
how my brain works when I see something.
At the root of this misconception is the photographic account of seeing:
The Photographic Account of Seeing:
Since the eye works like a camera, seeing is similar to taking photographs. Therefore, the
mind (or the brain) is like a photographic film.
Vision depends on:
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Vision
1. What is there when you open your eyes (how can it depend on what is not there!).
2. The physical constitution of the observer.
3. The relative position of the observer and the observed, and the environment (lighting,
fogginess, and so on).
4. Nothing else.
Consequences of the Photographic Account of Seeing:
1. You are not easily deceived by your visual system. "Seeing is believing." Provided that
vision is not impaired, it is a reliable source of knowledge about the external world.
2. Vision is not ambiguous in any way. We all see the same things in the same
environment. Vision is not subjective, and not laden with prior expectations (we don t
see what we want to see).
3. The mind is passive in observation. The mind does not construct what we see.
The Fallacies of the Photographic Account of Seeing:
1. You are easily deceived by your visual system.
2. The visual information provided by your eyes can be ambiguous.
3. Seeing is a constructive (active) process.
1. You are easily deceived by your visual system.
a. Side vision is blurry. We have the illusion of seeing clearly everywhere because we
move our eyes easily and frequently.
b. Gray on a background gradient.
c. Kanisza s triangle, illusory contours.
d. The Müller-Lyer illusion
2. Visual system can be ambiguous.
a. Different apparently square shapes produce the same 2D projections.
b. Monocular depth vision.
c. Necker s triangle.
3. Seeing is a constructive (active) process.
a. Kanisza s triangle.
b. Blind spot.
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Vision
Conclusion:
The photographic account does not work because, roughly speaking, it would imply that your
television can see. You cannot wire up your TV to sound an alarm each time a dog appears on
the screen. Still less, could it ever tell the difference between a dog and a painting of a dog. It
only records sequences of colored dots. It cannot interpret or understand what they mean.
The Homunculus Theory of Seeing:
Amend the photographic account slightly by supposing that there is some central "inner"
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