Posted by Estella on September 2, 2006, at 12:39:38
In reply to Re: Biopsychosocial vs Biological Reductionism, posted by finelinebob on September 1, 2006, at 19:41:35
> We do differ on a few key points. If what you mean by "fact" is an indisputable truth, I'd say you can have those in logics and semantics but not in science.
Oh dear... What do I mean by 'fact'. I guess I think facts are objective. There are dogs. That is a fact. We might believe that the proposition 'there are dogs' is true (in which case we would be right), we might believe that the proposition 'there are dogs' is false (in which case we would be wrong). So I guess I think that facts are objective and mind-independent whereas how we get to know facts is a difficult problem.
2+2=4 is a fact. It is arbitrary that the character '2' picks out the number two, and it is arbitrary that the character '+' picks out the mathematical function that it does. But *given that* the characters have the meaning that they do it is a fact (indeed a necessary fact) that 2+2=4.
Water = H2O is a fact. It is arbitrary that the word 'water' picks out the substance in the world. But *given that* the word attaches to the substance that it does it is a fact (indeed a necessary fact) that water = H2O.
(The Water = H2O example is controversial. Some people say Water = Whatever the best scientific theory tells us it is. It might be that future scientific theorising will show us that Water doesn't = H2O at all, rather it = something that we can't comprehend as yet. Regardless, the notion is that Water = Whatever the best scientific theory tells us it is and whatever that turns out to be it is a necessary fact that it is what it actually is).
> science is based on falsifiability and not verification...
Well... Both are used. There are studies where people claim they have found evidence to support their hypothesis.
> And objectivity is a fiction since all observation is theory-laden
Though it might be an objective matter which theory is the best.
> A closely related second point is that rationality is also a fiction based on the epistemology of empiricism.
?
There are objective measures of rationality. If I say 'I believe it is raining and I believe it is wet, but I don't believe it is wet' then something has gone wrong...Some people think of scientific models as useful fictions. Other people think of scientific models as mathematical objects.
> But, to continue the thought experiment and acknowledging that some "Primary Mover" started physics off on its merry way some 13.5 billion years ago...
Yeah. That hypothesis lies outside science. If you ask 'What was the cause of the first event within the natural world' then (if there was one) it is going to be a supernatural cause (hence it will lie beyond science) by definition.
> And assuming perfect replication and rigid determinism of a higher level by its predecessor.
The relation between levels is thought to be one of constitution (hence there is a one way logical dependence) rather than something like a causal dependence. As such there is no room for the higher levels to not be determined (in the logical sense) by the lower levels. No room to manouver at all. Can I think of an example... 2+2... = 4 as a matter of logic. So the precise arrangement of subatomic particles over to my right determine that there is a phone there. No room at all for the subatomic particles to be the way they are yet for a phone not to be there. But while 2+2=4 it is also the case that 1+1+1+1=4 and hence you can't work back from the phone (4) to the precise arrangement of subatomic particles (how you got the product of a sum).
>as long as you do not assume rigid determinism and perfect replication.
It is controversial whether indeterminacies on the sub-atomic level percolate up to indeterminacies on the atomic level. It is controversial whether the sub-atomic level is irreducibly indeterministic or whether there are missing variables. Mutation on the level of genes... Is probably logically dependent on deterministic processes at the level of atoms. It is possible that indeterminacies on the quantum level... Is logically dependent on deterministic processes at some lower level that we haven't managed to figure as yet.
> I don't know the chemical equivalents, but obviously in biology we have random mutations based on probabiltiy and by interactions with external agents (carcinogens, energetic photons).
Sometimes what people mean by 'random' is 'we can't find a pattern'. That doesn't entail that there isn't a pattern there to be found...
> Crushed rocks make a brick. Many bricks make a house. The habitation of houses by people make homes. Collections of homes make a city, and so on.
I like that example :-)
> Higher-level concepts in your system exhibit a one-to-many relationship with lower-level phenomena, not a one-to-one match.Yeah. That is called 'multiple realisability' or probably 'realizability' in US english.
A problem with the brain is neural plasticity. Different brains are like... Different trees or shrubs where there is similarity in overall shape and in certain features but also vast differences in how different individuals brains are wired. Like branches and twigs and leaves. There is considerable variation across the population. Considerable. One person might have a lesion in one particular site with a precise functional deficit as a consequence and another person might have a lesion in a similar site with no functional deficit as a consequence. Of course one could try and say that there are differences it is just that they are too small for us to notice. That might be right but it seems that a better explanation is that different peoples brains are wired differently so you can't map function very well between individuals. It is very complicated.Take A B C D E as people with x disorder.
Do an fMRI scan of them.
Superimpose one scan on another scan on the next scan etc (average the results).
You end up with a model (one scan) of 'people with x disorder'.Take F G H I J as normal controls.
Do an fMRI scan of them.
Superimpose one scan on another scan on the next scan etc (average the results).
You end up with a control (one scan) of 'normal people'.What I worry about is...
Take K L M N O as normal controls2.
Do an fMRI scan of them.
Superimpose one scan on another scan on the next scan etc (average the results).
You end up with controls2 (one scan) of 'normal people2'.Are there noticable differences between 'normal people' and 'normal people2'? I don't know the unit of measurement... What is the scan supposed to show? Neural activation (deduced from metabolisation of sugar or somesuch...). I don't know the scale... But you need to decide on how to assign colours to numerical differences. How you decide that will make a considerable difference for how normals and normals2 look similar / different. Kind of like choosing an appropriate scale so your graph is visually most striking.
Are there more differences between 'disorder x' and 'normals' than there is between 'normals' and 'normals2'? Just how similar is F to G anyway?
Is it more likely that A will have a brain more similar to 'normal' or to 'disorder x'?
I don't know... But these are my worries about the significance of fMRI findings. (Yes I appreciate that sample size is much larger).
poster:Estella
thread:680731
URL: http://www.dr-bob.org/babble/20060901/msgs/682297.html