4
Is physicalism self defeating?

J. B. S. Haldane said:

If my mental processes are determined wholly by the motions of atoms in my brain, I have no reason to suppose that my beliefs are true…and hence I have no reason for supposing my brain to be composed of atoms

If he’s right then belief in physicalism seems to undermine itself. What do you make of this?

Posted: November 1st 2009

Eric_PK

Here’s the full quote:

It seems to me immensely unlikely that mind is a mere by-product of matter. For if my mental processes are determined wholly by the motions of atoms in my brain I have no reason to suppose that my beliefs are true. They may be sound chemically, but that does not make them sound logically. And hence I have no reason for supposing my brain to be composed of atoms.

Haldane, 1927

This whole quotation resolves around the word “true”.

He basically argues that you can’t get to “true” from mindless physical processes.

I agree.

But since philosophers have been arguing about the meaning of truth and how to get there for thousands of years, I think his argument is pointless.

The whole point about science is that it’s not about what is true, it’s about what works.

Posted: November 2nd 2009

See all questions answered by Eric_PK

brian thomson www

This sounds like just another version of the “brain in a jar” argument. It’s certainly possible to argue that everything you sense is an illusion, as if you were living in a “Matrix”. Since your beliefs are derived through your senses, this can include your beliefs about the nature of matter itself, as Haldane implies.

I don’t have a problem with this. I have argued, in other questions, that it is unhelpful to argue this way, because if such an illusion is perfect, we have no way of finding out anything about it, far less doing anything about it. (If you have seen The Matrix, you may recall that the plot hinged on the ways that the illusion was imperfect: with no holes in the illusion, it would have been a very short movie!)

What solution does Haldane offer to this apparent conundrum? I don’t see one, unless he is appealing to something that is real yet non-physical? That’s quite a stretch. If you insist that your beliefs must be “True”, in some kind of absolute sense, then you may be tempted to fall in to that trap. My response to that is: don’t do that. Can you justify this expectation – that whatever you believe be absolutely true? I don’t think you can.

My experience of being an adult atheist includes “letting go” of such expectations. I don’t demand absolutes from anyone or anything, and neither am I prepared to twist my brain in to knots, trying to make the real world (as I see it) fit some abstract ideal not supported by evidence. I start with trying to see the world as it is, playing the hand that I have been dealt, and I take it from there. If my beliefs about the world, such as atomic theory, turn out to be not absolutely true, well, they are good enough to get the job done, and I can live with that. If it’s all in my head, how could I ever know?

Posted: November 2nd 2009

See all questions answered by brian thomson

logicel

If food is determined wholly by the motions of atoms within it, I have no reason to suppose food is true and hence I have no reason for supposing food is composed of atoms.

You can go on and on in this ridiculous manner.

The aspect which I can consider to be self-defeating is if I don’t eat food because I can’t be sure it is really is food, then I will become malnourished quickly. Ditto for not using my mind, as I will become rapidly mentally/emotionally starved.

Posted: November 2nd 2009

See all questions answered by logicel

bitbutter www

If my mental processes are determined wholly by the motions of atoms in my brain, I have no reason to suppose that my beliefs are true

This seems like a non-sequitur to me. It’s not obvious how the fact that the mind supervenes on the physical substrate of the brain, provides provides any extra reason to doubt the truth of beliefs we hold.

On the other hand, if I believed that the universe contained an invisible being who’d been known to 'harden peoples hearts’, deliberately sow confusion among humans, and alter physical existence by force of will, I would be a good deal less confident about what I thought I knew.

Posted: November 2nd 2009

See all questions answered by bitbutter

 

Is your atheism a problem in your religious family or school?
Talk about it at the atheist nexus forum