Mind, body and ME

Death is the failure of the aggregate of actions we call a body to keep working to maintain itself as that sort of aggregate. It is of rather little metaphysical significance. The individual actions that are souls within the body probably are immortal in a sense, in that they involve the entire universe (as any electron does in a Schrodinger type equation) back to the Big Bang, but each one is probably very evanescent in its non-trivial contribution to the history of a body, let alone the world. I rather suspect the significant history of a soul lasts 20 milliseconds.

 

Not going to pretend I followed all of that . But many thanks.

I get the sense from what you say that no matter how we humans strive to model the dynamic behaviours within our universe, they will always be no more than that - models attempting to mimic dynamic behaviours, but never actually mimicking the real physics of what is generating those behaviours; they do not need to, which is just as well if it really is unenvisageable.

 

So the truly hard thing to accept, which Leibniz, neuropsychology and physics all indicate we should accept with open arms, is that there is no 'real physics' beyond the mathematical pattern of the dynamics and our experience. What makes the mathematical patterns real is the ability to create patterns of experience in observers. But those patterns of experience are neither 'like' nor 'unlike' the distal dynamics that they tell a story about.

Real physical reality is not like anything in itself. Because there is no 'like anything' other than 'like something to me'. The idea that there is a God's eye view that will see what things are 'really like' is an illusion built into our brains and the way we remember images and sounds and roughnesses. Once one realises there is nothing to know beyond the knowing we are familiar with, one can relax, liberated from mystery. Poor Kant never really understood. There is no thing-in-itself that we cannot know. True metaphysics needs no smoke and mirrors. It is as clear as spring water.

 

... and zen !

 

Posts moved from Symptom perceptions, illness beliefs and coping in chronic fatigue syndrome, 2009, Moss-Morris

Although that is still not definitive as it assumes that our sense data and the laws of logic are accurate. But hey that kind of proof is about as good as we can get.

 

That’s why I included ‘I show that’ - I didn’t specify how I would prove it.

As for logic, I’m going to refer to this post:
https://philosophy.stackexchange.com/a/47440

 

I think that Hume was right in that all knowledge comes from experience. So any way in which you show or prove something has to at some level be reliant on experience and therefore not certain.

Just because a system of logic is sound and complete does not mean that its axioms are true. I would argue axioms are only true in so far as they are continually confirmed by our experience of the world.

 

I'm not so sure, I think something can be assumed to hold if it gives both results that do confirm our human experience and don't in other aspects, because models tend to not be general but specific. Are only concrete objects part of our human experience or are abstract objects as well and how do you define the difference? Who decides which experiences I value as more truthful (I think it is Hume who debates the differences in "prove", which doesn't exist in the classical sense in the physical world, and "evidence" at length but wouldn't axioms seemingly fall into a somewhat different category of undecidability)?

In that sense I think it is more so that a physicist (or scientist by extension) trying to explain experiences of the real world doesn't have to know what axioms are right in general to model something fruitful and that the philosopher or mathematician builds their house after having chosen in what they think will make a fruitful home. I don't think you can conclude anything about the truthfullness of axioms from that given that all physical observables in the world of the physicist/scientist don't tell you anything about the validity of the axioms the mathematician/philosopher builds their house with, as for instance the axiom of choice, is not observable. They can even decide to work with different systems where the abstract objects differ but the concrete ones don't. That is truth in the aforementioned sense has been removed entirely from the discussion.

All good models usually manage to model at least partially what they are supposed to model, but they tend to not model everything "correctly" and I see that being reflected in axioms and their "truth". One can certainly prove something without relying on human experience of that object rather than just having experience in proving things and in that world you can remove the subjective nature of experience by formalising such rules. The end result is "true" in the sense that you applied all your rules correctly once you had specified your building blocks, the nature of truth here being following agreement: In case people disagree about an end result, for example because it doesn't match their experience, things can be boiled down to the building blocks and then there isn't disagreement about the end result anymore just about the choice of building blocks. However, that means you obtain objects that both are not confirmed by your experience of the world and that are confirmed by your experience of the world (you might even go so far as saying that some purely abstract and paradoxical objects, for example in the Banach-Tarski construction, don't model all of your human experiences correctly but that it might model some other physical phenomena of your experience quite well).

In that sense I see axioms as not being true or false in a sense of provability, they are more so building blocks of a system and which building blocks one wants to use depends entirely about the constructor and what one wants to construct. The most common of these systems used in the world of mathematics, ZFC, will give you all the objects the scientist usually wants to live with but also throw up some other objects that are in some way counterintuitive and most certainly oppose your experience of the real world, they are paradoxical but as these weird phenomena do not exist outside of the abstract setting you can be as happy as ever. So you could go as far as saying "this axiom is obviously not true, but just as everbody else I'm very happy to use it", that is in the end the scientist tends to be pragmatic because we tend to deal with concrete objects where we can't get into trouble, but I'm unsure whether one can say one is part of human experience whilst the other isn't or that one is truer than the other because that notion of truth seems to be entirely subjective as well.

Of course one is entirely free to choose a different system, they exist and some have different preferences (but that debate tends to almost always be purely "historically motivated" rather than "truth" motivated) but you will have to live with the fact that other experiences of our world will not be met in the sense that other paradoxes will be thrown up. Switching between systems can beautifully allow you to understand which limitations your system will eventually entail which might not be such a stupid thing as there might be a universe very close to our own experience where the initial building steps are slightly different to how we usually start by building our house.

 

I think the objects themselves are not part of our human experience. It is our sense data which is the experience, and this data can be combined together to produce guesses about what the experience of an abstract object would be like. What convinced me of this is to imagine a brain that had no sensory data whatsoever. No visual, touch, taste, audible, olfactory data whatsoever.

How could such a consciousness "think" about anything. There would be no language, no impressions of physical objects, and no ideas. How could you ever come up with the axioms of math if concepts like addition, points, chance have no reference. Thinking requires something to think about. I am not sure that such a brain could even produce something like Descartes' I am thinking therefore I am existing. And even things that are already contained within the brain, like emotions, need some sort of outside stimulus to function.

Because of this, I think that all axioms must be observable in some sense. By this I mean we have evidence that they are "true" only in so far as they continue to produce results that fit with our other observations about the world. In Euclidian geometry, the 5th postulate always seem to match our observations about the world until we discovered conditions under which it didn't. This is how I think about all axioms, that they are true only in so far as the continue to match our understanding of reality. It is a pragmatic decision to assume that they are true, and so far it has paid off. So I think we agree that axioms (just like everything) aren't really true or false, they either are useful, and match our experience of reality (in some way), or they don't and we reject them. I think the disagreement comes down to how we come up with these fundamental building blocks. I think it is through observation and experience.

In cases where some results don't seemed to be confirmed by our human experience, we only accept those results in so far as we accept the more foundational premises on which it is built. The basic axioms of logic and math are so universally confirmed by our experience that we are forced to accept some things which seem to conflict with our experience as to reject it would require rejecting some more fundamentally held experience of how the world works.

 

But all those sense data are generated inside the brain. They co-vary with events outside very often but they are all internal.

It is probably unwise to get into a full blown metaphysical debate but I am quite sure that Hume was wrong about empiricism, and Leibniz provides the reasons.

The key point is that our knowledge must draw heavily on rules built in to the way our brains compute that have evolved because they themselves reflect rules outside (being made of the same dynamic structure). When a child realises that they know that the three angles of a triangle must add up to 180 degrees that knowledge does not come from empirical testing. It comes from 'seeing why'. The brain has resources to tell its inner subjects that something must be true, independent of any specific data from outside.

 

Ill have to go read some Leibniz then. And yes probably best to avoid a full on debate but just a few quick points.

I agree that the sense data is generated inside the brain. But why should we expect anything to go on inside a brain without inputs. Is there an example of something that could be generated by a brain with no inputs? I guess that was Hume's question, and although he came up with the missing shade of blue, I think we know now that that really doesn't disprove his point.

'seeing why' to me is just the empirical testing. Every triangle we see always has angles that add up to 180 degrees. How would we see why this happens if we have no concept of triangles or degrees. I agree that the brain has rules that evolved which we call logic, but that requires some inputs and is useless without them.

 

Can you define the external and internal in relation to the ‘inputs’? External to a single neuron? A collection of neurons? The physical mass we call the brain? The brain’s immediate surroundings? The body?

 

I think Hume's claim was something different - that all knowledge came from the senses. This was to counter the argument that some knowledge comes from innate reason. Leibniz's claim is that knowledge comes from a combination of sensory input and reason.

And within window of time the brain can generate knowledge without any current input. That is basically how we construct hypotheses and convince ourselves that they must be valid.

Seeing why is independent of empirical testing. Knowing that the angles of a triangle must add up to 180 degrees is quite independent of checking examples. I know it must be true for every triangle in a Euclidian plane that I have never seen and never will see.

The thing that interests me most is that a computer could not possibly know this because a computer has no computations that themselves involve geometric complexity, so there is no possible source of knowing. In contrast it is quite likely that computations in neurons do involve geometric complexity.

 

I agree that Hume's argument is that all knowledge ultimately comes from the senses. But I think Hume would agree that we can have knowledge of things we haven't had impressions of; and the process of stringing together impressions into complex thoughts is reason. We can produce the idea of a unicorn without experiencing a unicorn. But that isn't because reason produced something new ex nihilo, it just used our previous impressions to generate a complex idea.

The example of the brain with no inputs is argue that the sensory input is required for reason to function. If that is the case, then reason only acts on the inputs that the brain receives and doesn't form any new a-priori knowledge. If reason doesn't produce any completely new knowledge, it must ultimately goes back to some sensory input.

The way the brain process information is clearly complex, and so it isn't possible to show what sense information reason acts on. But if any knowledge can actually be produced directly from reason, then it should be possible for an input less brain to generate knowledge, which I don't think is the case.

 

I don't think it is independent of empirical testing. We may not empirically test the angles of a triangle directly, but that proof relies on axioms that we have imperially tested.

To know that the angles add up to 180 degrees, we must have experienced Euclid's postulates. Because of this we can deduce that the angles add up to 180 degrees. But that knowledge isn't a new thing, it is just using reason to manipulate the simple impressions of Euclid's postulates. If we didn't experience that a line can be drawn between two points we can't know that the angles add up to 180 degrees.

We can also say we know the angles of a triangle add up to 180 degrees for other reasons, say someone you trust told you. But that too relies on the experiences you have had with that person in the past which leads you to "know" they are trustworthy.

 

I like to imagine a brain in a vat without any nerves attached. Maybe that brain would still get some inputs, but hypothetically we could cap the nerve endings such that no signal gets inputted.

It would be like seeing out our your toe, or smelling through our TV, in each case no signal arrives at your brain.

 

But that assumes that knowledge is simply having ideas and impressions. It can be quite other things like knowing why the angles of a triangle must be 180°. That is what is new. I don't think you can produce new a priori knowledge - more or less by definition. But as Plato/Socrates argued, we can find a priori knowledge within our brains.

I don't think that follows. Why do we have to posit that a brain has no input? Reasoning is not just stringing together impressions or ideas. I have published a theory of time that says that the word time conflates two quite different concepts - sequence and metric. Having identified that you can solve all the so-called puzzles of quantum theory. If that is knowledge how did it just come from stringing together impressions? !!

 

But we do not experience a line. Our brain makes up the idea of a line having had certain sensory inputs. Lines do not exist in the outside world.

You do not have to experience Euclid's postulates to know that the angles always add up to 180°. I was never taught about Euclid at school. The teacher just showed us that you can convince yourself that it must be true, without any reference to Euclid. You don't even have to have a protractor or an idea of degrees.

 

There must be some reason you were convinced it was true? How could be believe that certain angles add to 180° if you don't know about degrees? If you met someone who had no concept of geometry they wouldn't just know that the angles add up to 180°. You'd have to teach them that that is the case, starting from basic principles and working your way up.

This is how it works at school. You start with things that you experience to be true. Such as having one thing and putting another thing with it, meaning you now have two things. Knowing this, we can then use this idea to see that if we add one group for every unit in another group we get multiplication. The human experience is learning things from more basic things that come from our observations.

I as is the case with Hume, don't have a proof this is the case. But I can't find an example of knowledge that we can posses apart from our experience of the world. If there is knowledge we can have that doesn't rely on sense data (ie that we could still posses with no sensory inputs) then I would love to know.

 

Where did these ideas come from if not from impressions? Where they created out of nothing? If your brain can create knowledge apart from sense data, why can't an input less brain do that too?