Functionalism fun.

So, functionalism. Us materialist-connectionist types tend to be big functionalists, even if connectionism includes a certain structuralist element. Since I think functionalism goes hand-in-hand with token physicalism (as opposed to type physicalism), this makes more sense than it may seem at first glance.

I probably owe some definitions here.

Functionalism is the philosophy that what things are or how they are structured matters less than what they do. Even for simple objects, functionalists believe function is more important than form. It doesn’t matter what a wrench is shaped like so long as you have a gripping lever of some kind. Birds and bats both fly. Brain and computers… well, that’s a big argument.

Structuralism is the philosophy that the structure and organization of things is what matters. This idea is mostly obsolete, though it does guide a lot of its successors. Humans, for example, rely heavily on the organization of our atoms. The same atoms in a pile are very different than when they’re human-shaped.

But that’s an interaction of functionalism and structuralism. We need to be in the right shape, but only insofar as our shape can preserve our function. If you replace my arm with a robotic arm, it doesn’t change my being a human or a person, though my structure has changed, because my function remains.

In fact, you could replace me piece by piece, even using foreign structures like treads instead of legs, and I would still be me and I would still be a person, because my function would not change. Even my brain, if it were transferred or translated to a sufficiently sophisticated computer, would be structurally different but not functionally different.

‘Substrate neutral’ is a phrase to remember here. Functionalism says it’s not what things are built of or built on, but what they do. If a computer chip does the same thing as your brainstem, it’s functionally a brainstem even if it’s silicon and gold and transistors, instead of carbon etc. and made of neurons.

I mentioned physicalism above. Scientists, being materialists and naturalists and monists, are physicalists (except for compartmentalizing religious scientists and physicists waxing philosophic and giving the rest of us no end of trouble explaining what they’re actually saying when they say ‘spiritual’).

Token physicalism states that specific mental effects, such as feeling a pinprick or imagining a face, are physical effects. It does not, however, specify the mechanism by which this happens, and is thus *ta-da* substrate neutral. Type physicalism, on the other hand, associates whole categories of mental effects with specific physical effects, such as pain reception via nociceptive nerves. This would suggests that animals with different physiologies, for example, could not experience the same mental effects.

I’ll devote a whole post one of these days to qualia – hopefully I’ll be able to keep a tight rein on my language.

Where am I going with this?

It seems like I’m drawing a contrast between structuralism and functionalism, with a weird diversion into species of physicalism. The fact is, functionalism and structuralism are related. Functionalists do not claim that types of function rely on specific structures (type physicalism). However, specific functions in specific agents, objects, or artifacts, do rely on their structure for their function (token physicalism).

I might be stretching the association a bit. I’m not a philosophy major, so I’ll try to sum up with how neuroscientists (or at least, the ones I agree with) see things.

1. Mental processes are physical. Anything that happens in our minds happens in our brains – mental events are physical events. This is a monist position, and it’s hard to defend anything else, unless you take Popper’s position (which is more of a social or informational monist position despite what he claims).

2. Mental processes are generally substrate neutral. That is, the specific materials and organization of the ‘brain’ matter less than the fact that it functions as a brain. Thus, there’s no reason why a computer could not have emotions, or be introspective about its motives.

3. Mental processes are specifically structure-dependent. That is, in a specific agent’s function would be disrupted by a disruption of its structure. This does not preclude the adaptation of new structures to existing or previous functions, but does mean that within an agent structure plays an important element. Computers and humans can both sleep, but humans would be definitely impaired if their thalamocortical relays were cut off.

To sum up: things are physical, even if they’re mental. Function matters most; it relies, however, on a general structure but not a specific structure. Different things can have the same function with different structures.

Non-manifest truth, induction, and theories

Last week I wrote about the idea that truth is manifest, obvious to those who look without prejudice.  Several things come of this, including the conspiracy theory of ignorance, and the idea that others who disagree with what you claim to be true are in some way sinful, prejudiced, or mislead.

It also leads to the idea of science via induction.  Popper’s opposition to this idea is one of the main features of his philosophy of science, and I’ve not yet found a reason to disagree with him.

Induction proceeds like this: I see things occurring in the world.  For example, I might see a white sheep.  Eventually, I will observe many white sheep.  Therefore, as a general rule, sheep are white.  Every white sheep I see ‘verifies’ my theory of the whiteness of sheep.  Observations, he argues, cannot have any value except in light of a pre-existing theory, even if the theories are ‘sheep wool has colours’, ‘white is a colour found with sheep’.  Rather, what we start from is a theory – ‘sheep are white’ – and then proceed to test that theory via observation.

I’ll try to return to this question of induction vs. deduction via theory more, because I think it is very important.

Truly scientific theories, according to Popper, are not formulated by observing the self-evident truth of things.  Instead, theories are first formulated based on prior theories, which have either been refuted or not.  Falsifiability, whereby a theory can be refuted, is a necessary component of any scientific theory, according to Popper.  We cannot support our case through bulk of observation (where would our cut-offs be for the number of necessary observation?) but must instead attempt to refute our theory.  Theories which have survived many strict tests are then to be considered better approximations of the truth than ones which have been tested less rigorously.

I’ll finish by describing some conclusions Popper has drawn regarding scientific theories.

1. It is easy to confirm or verify theories by observation, when we look for confirmations.  If you’ve ever heard of confirmation bias, then you will understand why that is.

2. Confirmations count only if they result from risky predictions.  If your observations run counter to what you would have expected before formulating your theory, so that you expected to find a result which would have been impossible in light of your theory, they can be said to ‘confirm’ the theory.

3. Every valid scientific theory is prohibitory.  The theory should lay out things that cannot happen if the theory is correct.  And the more things the theory forbids, the better.  A very general theory, under which many things are possible, is not as testable as one which greatly restricts possible events.  This is similar to the idea that it is easier to make a list of objects which aren’t in a closed box than to make a list of the items which could be in the box.

4. A theory which cannot be refuted in any way is not a scientific theory.  Irrefutability is a weakness, not a strength, because a theory which is correct no matter your potential findings is meaningless, because it either prohibits everything or nothing.

5. Every sincere test of a theory is one which attempts to falsify or refute the theory.  Testability is a measure of falsifiability.  Not all theories are equally testable – ones which are more exposed to refutation, which are ‘riskier’, are more valuable if we find ourselves unable to refute them.

6. Confirming or corroborating evidence is only valid if it results from a serious attempt to falsify the theory.  A theory which survives multiple attempts to refute it can be said to be confirmed or corroborated by the evidence.

7. Theories can be modified post hoc to accommodate a refutation of part of that theory, but this lowers the theory’s value as it is no longer as prohibitory as before.

This last point is sharply debated, especially by Thomas Kuhn.  When I get through Popper and have some time to tackle his major book, I’ll try to address some of their disputes.

Manifest truth and ignorance

I’ve been reading Conjectures and Refutations by Karl Popper, so a number of my posts for the next while will draw heavily on the material presented in this book. In it, Popper lays out his philosophy of science, his dismissal of the idea of inductive logic, and his demarcation between science and pseudoscience. There’s a bit more to it than that, but I’m only a couple chapters in.

Here, I plan on discussing two interrelated ideas: one, the idea that truth is manifest and the subsequent idea that there is a conspiracy of ignorance.

Essentially, Popper claims the Renaissance and later the Enlightenment were based off of an optimistic epistemology, that man was able to discern truth and acquire knowledge simply by casting off prejudice and bias and using his observational abilities to see the truth manifest in Nature. Further, man possesses rational faculties which allow him to intellectually intuit the difference between truth and falsehood. Popper, while noting the origin of these ideas in Parmenides, Socrates, and Plato, places most of the blame for the idea of manifest truth on Descartes and Bacon.

Descartes thought the truth was manifest because of veracitas dei – what we clearly and distinctly see to be true must be true, otherwise God would be deceiving us. Bacon declared the veracitas naturae – the truth of nature – and that anyone who reads the open book of nature with their mind unpoisoned by prejudice will see the truth.

Now, obviously this attitude has its problems. The primary one regards error. If the truth is manifest, how can we ever be in error? By wilful and even sinful refusal to see the truth, through inculcated prejudice from tradition or culture or dogma, or through active conspiracy from others to conceal the truth.

The conspiracy theory of ignorance “interprets ignorance not as a mere lack of knowledge but as the work of some sinister power, the source of impure and evil influences which pervert and poison our minds and instil in us the habit of resistance to knowledge.”

This attitude has prevailed throughout much of history, in institutions such as the Church, Marxism, and even among some atheists. As an atheist, I often encounter a belief among believers that I am simply refusing to acknowledge the existence of god, rather than having reasons for my sincere non-belief.

Sincerity often plays a part in this – when we ‘know’ something, we often wonder how others who do not agree with our view can do so. If the truth is obvious, something must be wrong with those who do not see it. They must be stupid, or vicious, or wicked, or mislead. Personally, when it comes to less ambiguous questions (such as the age of the Earth) I am more inclined to blame ignorance of the facts rather than any of the above.

So if I’m arguing (along with Popper) that truth is not manifest, how do we gain true knowledge? If there is no wilful or conspiratorial ignorance, how is there error? Well, I’ll save that for my next post.