@FBM,
Quote:Can you explain how it might be relevant to the workings of the macroscopic brain?
I could just say that there are, in a modern scientific outlook, causes without cause e.g. at quantum level. If it can happen to particles, why can't it happen to something else?
It's a mistake IMO to consider that quantum laws only apply at the microscopic level and not at "our level". We too are composed of microscopic elements. We might suffer or even die from radioactivity when exposed to it, yet radioactivity is inherently a quantum event. Radioactivity can also randomly cause positive mutations that may get carried into the species gene pool... We live in the same world as particles do.
This said, quantum objects seem to follow probabilities and are thus predictable at the level of large numbers. E.g. the radioactive decay of one particular carbon-14 atom into a nitrogen-14 atom is unpredictable: nobody can say when it will happen; but the
rhythm of decay of large numbers of such atoms is predictable through probabilities, allowing carbon dating.
The same principle applies to biochemistry: while the timing of a particular chemical interaction involving a particular pair of molecules is generally unpredictable, some predictions can be made at the level of large numbers, and thus chemists can predict the speed at which thousands of molecules will react with one another.
Therefore, you would have a point IF the brain was one large unstructured population of chemicals: the reactions happening at the level of the whole 'soup' would be deterministic, by virtue of them involving a large number of chemicals. BUT the brain is not a soup. It has a very fine and complex
structure made of complex meso-structures (neurons), themselves made of complex micro-structures (dentrites, synapses, myelin, etc.) themselves made of complex nano-structures (e.g. cell walls covered with chemical receptors of different kinds and able to interact with scores of hormones and neurotransmitters). The nano and micro levels are partly unpredictable in their individual behavior, because they deal with small numbers of molecules and chemical reactions. And the meso and macro-levels are not necessarily adding up these micro-level events in an additive way where they would annul one another, as happens in large unstructured populations. Instead the macro-structure is
combining micro-level events into a broad synthetic picture that is more than the sum of its parts.
Think of two painters using two paints, yellow and blue. One painter is mixing his two colors to make a nice green color, and he and paints his whole canvas with that green. That's a metaphor for unstructured, soup-like large number aggregation: the whole erases the variability of the parts. The other painter uses each color separately in patches, thus painting a picture of say a yellow parrot over a blue sky background, and adding a few touches of green here or there on the parrot. That's a metaphor for a structured combination of micro-elements into a macro-picture that retains the original colors and their variability. The first painter can only paint one easily predictable (green) picture, while the second can paint an infinite number of new, original pictures.
The brain IMO is like the second painter. It may very well retains the unpredictable, underterminist feature of small scale biochemistry and physics.
. Having disagreements doesn't have to lead to hate. I still love their music.
