>>>This is a post from my second calendar year of blogging (i.e. the January after I started). I like it because it reminds me of what it’s like to be really, deeply perplexed by a philosophical issue. Nowadays, I’m used to thinking that I don’t know what to say about a philosophical issue, but I’m more comfortable accepting it and setting it aside–too comfortable, maybe. Here it is. <<<
It’s been awhile since I’ve written about epistemology, and with the next philosophy carnival fast approaching, I think I’ll take another go at it.
A common response to radically skeptical thesis (we can’t know if the sun will rise tomorrow, we can’t know whether we’re living in a Matrix-type world or not) is, “well, true, but if the sun won’t rise tomorrow, there’s nothing we can do about it.
In toyed with a broader form of that idea in a previous post on proof. The broad form is “reject possibilities that cannot be evaluated on the evidence, because if they’re true, there’s nothing we can do about it.” For example, if there’s some evidence that we do in fact live in a Matrix-world, we could consider the evidence, but we must reject the idea of a Matrix-world that is impossible to identify as such. I still think that strategy is the best one, but I’m not sure the “there’s nothing we can do about it” justification works.
The problem is one that occured to me when reading about William Dembski’s abuse of no free lunch theorems. The skinny: he claimed that the theorems show no algorithm is any better or worse than random seaching for finding the high point in a fitness function, a measure of how well something works. This means natural selection won’t work any better than random generation of organisms, and cannot generate the life forms we see. The flaw in this argument is that the theorems were for the set of all possible fitness functions – a set in which most functions are completely chaotic. The real-world scenarios that evolution deals with look more like rolling hills, however. (See the pictures in the link, they show this better than I could put it into words.) There may be lots of hypothetical random worlds where natural selection wouldn’t work, but ours isn’t one of them.
Now back to epistemology. Why not assume that worlds where “reject possibilities that cannot be evaluated on the evidence” works make up a tiny fraction of all possible worlds? Is there any a priori grounds on which we can decide whether a world of testable hypothesis has a high, 50/50, or infinitesimal chance of existing? I’m not sure.
This derives from a problem in determining a priori probabilities more generally. One person might say, “God either exists or he doesn’t, that’s a 50/50 chance,” and another might say, “The standard God (omnipotent, etc.) is only one possibility of an infinity, so that’s an infinitesimal chance.” How do you decide between them a priori? You can’t. That causes serious trouble for any theory of knowledge that attempts to start with certain probabilities.
My main problem with these questions is the fact that philosophers waste energy on thinking about things that realistically will never happen – the sun will rise tomorrow because the world will continue to rotate and the sun isn’t going to become a red giant for 50 billion years, we have no evidence that we are living in a Matrix world and it’s disingenuous to speculate on it without an empirical hook, and suggesting that worlds where “reject possibilities that cannot be evaluated on the evidence” make up a tiny fraction of all possible worlds – aside from the fact that our world is the only world that has HAPPENED, according to the principles of logic, mathematics, physics, chemistry, and biology that make our universe – is tantamount to saying there’s a possibility that there’s a giant flying teapot on the other side of the sun. There is no proof. Please please please stand up for empiricism. You say that you’re a philosophy student frequently, and you are, but you’re also a neuroscience student and quite frankly you should know better than to skate over evidence, especially recently-discovered evidence.
It still baffles me why you choose to study consciousness through philosophy – your work is your choice, but will it achieve your ends? Is studying philosophy more important to you than answering your questions about consciousness? Or do you have more things that require studying philosophy?
‘disingenuous’ was not the word I was looking for. ‘Foolish’ is more apt to describe the sheer inanity of speculation without, it seems, adequate information of the logical and physical principles governing what one is speculating about.
One has to consider, though, since this is an archived post, whether your view on what you posted then has changed not so much.