You see Samuel Johnson as a realist?
I think I started off a naive realist, became a realist and quickly became
confounded by the absurdity of the position. If I 'understood that there can
be things like optical illusions', I did so honestly, they told me something
very clear about the nature of perception which makes realism look as naive
as naive realism.
We have strong perceptions when we dream, we dont always know we are
dreaming. Sense data is what we are directly aware of, mental
representations. When we are not dreaming, we are still only directly aware
of sense data. However justifiable, the external world is an inference from
these representations whatever they are instantiated in. How can I on the
one hand be told that light falls upon my retina creating an image that is
upside down, then be told that I see things directly and as they are? It
makes no sense. Its blind hope and is obviously wrong. The world does not
look upside down. The very fact the image gets flipped the right way up is
enough to demonstrate I am in the grip of a cognitive representation. No.
Berkley is right on that score.
with regards to the question of whether Johnson refuted Berkley. I cant see
how he did.
From: "Lee Corbin" <[EMAIL PROTECTED]>
Reply-To: <[EMAIL PROTECTED]>
To: "EverythingList" <email@example.com>
Subject: RE: What We Can Know About the World
Date: Wed, 27 Jul 2005 11:11:33 -0700
> >>Samuel Johnson did refute Berkeley.
> The main thrust of Berkley's argument is to show that sensory perception
> indirect, and therefore the existence of a material cause for those
> perceptions is an unjustified inference in contravention of Occam's
> The argument that the look, texture, smell, taste and sound of an object
> apprehended indirectly is successful in my opinion, and I don't feel any
> to defend it unless someone really thinks a defence is required.
Do *you* contend that the existence of material causes for your
perceptions is unjustified? Good grief.
As for your other statement, these senses are indeed, just as you
say, apprehended indirectly. (That's the difference between realists
and naive realists, e.g., children.) Of course there is no need for
you to defend that, because no one here would disagree.
> Afterall, on any view there is a translation of 'signals' of many
> different forms (light waves, sound waves) , into various 'signals'
> of the same form (neurons firing) which become synaesthetically
> unified into a whole, such that we associate the smell, taste,
> colour and texture of say an orange, as being qualities of the
> same object.
> ...Berkley's move here is to insist that it we have enough
> information now to create the appearance of a 3 dimensional
> world out of elements that are not intrinsically extended.
I'm not sure what you mean. By elements already in the brain?
Yes, that's true. But they got into the brain by the aforementioned
processes, as you know. Don't lose sight of the fact that almost
all the information came from outside.
> By Occam then, we should not infer something for which there is no
> requirement - however firmly that inference has been imbedded in us.
> We should stick to using what we can know directly. Perception.
You don't know all this complicated crap (neurons, perception,
inference, the whole nine yards) nearly as well as you know
the monitor in front of you. The problem is the word "know".
The first things you knew consciously, and knew well, were things
outside your skin: your mother and father, and tables and chairs.
Let's resist the temptation to begin using words in other ways.
Much, much later you ceased being a naive realist and became a
realist. You understood that there can be things like optical
illusions, and altered states of consciousness. You even understood
that your own exalted consciousness is not anything to be utterly
depended upon, because one can be sick or crazy. (If it hasn't
happened to you yet, then just stay around a few more decades.)
Build carefully upon what is simple and knowable, and keep the
wild theories to a minimum. Even then, the world is hardly
simple, but at least we've got a chance.
> In other words, dualists and materialists contravene Occam, not
> idealists. I don't see how Johnson refuted that.
Materialists do not contravene Occam. The simplest explanation is
that there is a world "out there" and that our brains are survival
machines designed by evolution to thrive in it. The phantasms that
occasionally infest our awareness and consciousness causally arise
as side-effects of how our brains work, that's all.
The simplest explanation does *not* start with perceptions and
all the rest of that stuff, for a number of reasons. The primary
reason is that you can't truly communicate them to others---after
all, your brain may not work the same as theirs. As Wittgenstein
said, "Of what we cannot speak thereof we must be silent".
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