Friday, September 25, 2020

Space news

A probe will touch down for just a few seconds on 101955 Bennu, an Earth-crossing asteroid, in less than a month, collect some samples, and then return to Earth in 2023. That is pretty cool. It'll look something like this (try to ignore the soundtrack):

Saturday, September 19, 2020

Searle contra Dennett

In 1992 when John Searle published The Rediscovery of the Mind. Daniel Dennett reviewed the book in The Journal of Philosophy, and you can read his review here. Then Searle published a critique of several then-recent books on philosophy of mind, including Dennett's Consciousness Explained in his column in The New York Review of Books, which you can read here: scroll down to the bottom, or do a page search on "Quotes 11".

Here's where it gets interesting: Dennett then wrote a letter to the NYRB blasting Searle, to which Searle responded, and you can read both here. Prior to this, Searle and Dennett were, I think, friendly rivals. Not after. Dennett writes, "Searle doesn't have a program of research. He has a set of home truths to defend. They land him in paradox after paradox, but so long as he doesn't address the critics who point this out, who’ll ever know? ... There is not room in these pages for Searle to repair fifteen years of disregard, so no one should expect him to make good here, but if he would be so kind as to tell us where and when he intends to respond to his critics with the attention and accuracy they deserve, we will know when to resume paying attention to his claims."

I have to agree with Searle's assessment of Dennett's accusations: "Dennett’s letter has a peculiar rhetorical quality in that he is constantly referring to some devastating argument against me that he never actually states. The crushing argument is always just offstage, in some review he or somebody else wrote or some book he published years ago, but he can’t quite be bothered to state the argument now."

I should also point out that I tend to agree with Searle's argument:

An intuition in [Dennett's] sense is just something one feels inclined to believe, and such intuitions often turn out to be false. For example, people have intuitions about space and time that have been refuted by relativity theory in physics. In my review, I gave an example of an intuition about consciousness that has been refuted by neurobiology: the commonsense intuition that our pain in the arm is actually located in the physical space of the arm. But the very existence of my conscious states is not similarly a matter for my intuitions. The refutable intuitions I mentioned require a distinction between how things seem to me and how they really are, a distinction between appearance and reality. But where the existence of conscious states is concerned, you can’t make the distinction between appearance and reality, because the existence of the appearance is the reality in question. If it consciously seems to me that I am conscious, then I am conscious. It is not a matter of “intuitions,” of something I feel inclined to say. Nor is it a matter of methodology. Rather it is just a plain fact about me—and every other normal human being—that we have sensations and other sorts of conscious states.

However, I am suspicious of making it into an argument because it allows Dennett and others (like the Churchlands) to argue that you can make a distinction between appearance and reality with regards to conscious states, and their philosophies of mind explain how. All they have to do is deny that premise. Certainly that's not a very plausible option, but they could do it. I'm not sure if you could prove Searle's point via an argument to someone who was dead-set against it.

Sunday, September 13, 2020

Arguing from Authoritah

I sometimes get frustrated by common logical misunderstandings. Here's one that just boils my butternut squash: when people think that, since there are fallacies of appealing to authority, all appeals to authority are fallacious. This is not the case. In informal logic (inductive and abductive inference) appeals to authority are fallacious when the authority is an authority in an unrelated field. The fallacy does not rest in the appeal to authority per se but it in the irrelevancy of the authority's authority. For example, if you want to find out whether Newton or Leibniz discovered calculus first, I wouldn't ask someone who's an authority in pharmacological science. Of course, this person may have researched the subject such that they are uniquely situated to answer the question, but if we appeal to the fact that she is an authority, by virtue of her standing in pharmacology, we commit a fallacious appeal to authority.

That may seem easy, but people tend to strongly react against it. Here, for example, is a standard example of a fallacious appeal to authority. 

See, Einstein was a physicist. His area where he could speak as an authority is physics and other closely related fields. He was neither an expert nor an authority in political science or international diplomacy. Was he really, really smart? Yes, of course. Shouldn't we accept his claims about political science and international diplomacy by virtue of his extreme smartness? NO. That is a fallacious appeal to authority. His statement might be right (spoiler: it isn't), he might even be in a good position to affirm it, but it is outside his field of expertise. This is precisely why he declined the offer to be one of the first presidents of Israel.

But there are valid appeals to authority. Traditionally in Western civilization arguments from authority have been considered the weakest possible type of argument, at least according to the medieval Christian theologians. The reason it's extremely weak is because it doesn't involve you coming into direct contact with the truth of a matter: you're just accepting it because someone else has supposedly come into contact with it. But it's still a valid argument merely because, well, let's let Asimov say it:

What this counts for is a matter of dispute among philosophers. There are plenty who say that it only has relevance alongside other arguments. Others say it has strength by itself, but not so much to overturn an assertion. And some just reject the whole shebang.

Where people tend to gloss over the distinctions between valid and invalid appeals to authority is in appeals to science. Authority, supposedly, is of the old system, but science and a rejection of authority is the new system. Ignoring the point that the old system explicitly specified valid arguments from authority as the weakest of all arguments, science is completely beholden to authority. The glory and strength of science comes from its ability to challenge authorities -- background assumptions, traditional modes of understanding -- but of course the individual scientist cannot challenge all authorities. In order to get any work done, she has to accept the vast majority of claims on the basis of the authority of those who made them. She has to build up from what others have already accomplished, and this requires her to accept their claims on the basis of their authority. And of course the non-scientist has to accept scientific claims on the basis of the authority of the scientists who make the claims and the strong authority of science in general. I'm not challenging science at all, by the way, I'm just pointing out that a) appealing to authority isn't intrinsically bad and b) appeals to authority cannot realistically be removed, even from science. If your concept of science doesn't allow this, you're probably thinking of it as fundamentally iconoclastic rather than truth seeking. (Having said that, I'm writing these posts because I thoroughly enjoy telling people that they're wrong. So maybe we're even.)

The rabbit hole goes much deeper, of course. Does all this apply to individual authorities, or should it be reserved for the consensus of authorities? Can the collective efforts of the scientific community avoid appealing to authority even if the individual scientist can't? And who gets to decide who qualifies as an authority -- and who gave them that authority?

Monday, September 7, 2020

The Modal Ontological Argument

Arguments for and against the existence of God constitute one of the main topics in philosophy over the last few thousand years. By far, one of the craziest family of arguments is ontological arguments. They claim that the concept of God entails his actual existence. God is, by definition, the supreme being, the greatest conceivable being, the maximally great being, the perfect being, the being greater than which none can be thought. But if our conception of God is that he doesn't exist, he wouldn't be the greatest conceivable being since we could conceive of him existing and hence being even greater. Therefore, God must exist. Right? Anyone? Hello?

Ontological arguments sound like riddles, but some of the greatest intellects throughout history have defended them. Just in the last 100 years we've had Kurt Gödel (inarguably the greatest logician of the 20th century), Norman Malcolm, Alvin Plantinga, and Charles Hartshorne all defending versions of it. The standard objection to ontological arguments, from Kant, is that they treat existence as if it were a property a being could have or fail to have. But a being that failed to have existence wouldn't be a being at all. The recent counterargument is that this would only apply to Descartes's ontological argument, not to those of others, like Anselm's (or, for that matter, Kant's).

The contemporary versions use modal logic. This is basically the logic of possibility and necessity. If it's logically possible for you to do or be something -- say, waking up one morning as a giant cockroach -- then you have the modal property of "possibly existing as a cockroach." The weird thing is that, if it is possible for you to wake up one morning as a cockroach, then this modal property would not itself be a possible property you may or may not have, it would be an actual property. If something is possible, then its possibility is necessary (possible in all possible worlds), and if it's necessary, it's actual. So if it's possible you may wake up as a cockroach, then you actually have the modal property of "possibly existing as a cockroach." This sounds weird but it's a basic premise in modal logic (axiom S5) and as far as I know, it is uncontested in logical and philosophical circles.

So: say God is the maximally great being -- he has all positive properties, has them without limit, and has no negative properties. If this is logically possible, then God exists in at least one possible world. Now say God exists in only one possible world. Then he would lack the modal property of "possibly existing in world 2," and so wouldn't be maximally great. OK, so he has the property of possibly existing in worlds 1 and 2 and that's it. But then he lacks the modal property of "possibly existing in world 3." Now say he has the modal properties of "possibly existing in all possible worlds but one." Then he would lack the modal property of "possibly existing in that one world," and by lacking that modal property, wouldn't be maximally great. So if God exists in one possible world, he exists in all possible worlds. And the real world is a possible world, since if something is actual, it must be possible. Another way to say this is that any maximally great being worth its salt would exist necessarily, not just contingently; and if a necessarily existing being exists in one possible world, it exists in all possible worlds. Here's a rundown.

1. A maximally great being (God) is logically possible.
2. Therefore, a maximally great being exists in at least one possible world.
3. Therefore, a maximally great being exists in all possible worlds (otherwise he wouldn't be maximally great).
4. Therefore, a maximally great being exists in the actual world.
5. Therefore, a maximally great being (still God) exists.

There are some very interesting things about this, each one leading to the next. First, virtually every step in this argument is uncontroversial among logicians and philosophers, including atheists. But, second, there's a way to avoid the conclusion: deny the first premise. Deny that God, a maximally great being, is logically possible. Then God doesn't exist in any possible world. In fact, Plantinga, one of this argument's advocates, explicitly makes this point. Third, this means that God either exists in no possible worlds or all possible worlds. He either can't exist or can't not exist. He's either logically impossible or logically necessary. Fourth, since in order to say that God does not exist we have to say God cannot exist, the atheist bears the burden of proof. They must show that it is logically impossible for God to exist, that a maximally great being entails a logical contradiction. The theist only has to maintain that it's logically possible. But you don't have to prove something is logically possible unless you have a reason to think it may not be.

Naturally, one of the main objections to God is precisely that a maximally great being entails logical contradictions. For example, such a being would be maximally merciful but also maximally just. But these are, allegedly, incompatible since perfect justice would conflict with perfect mercy. Some individual traits are accused of being incoherent: could a maximally powerful (omnipotent) being create a stone so big that even he couldn't move it? If he can't, then there's something he can't do: make that stone. If he can, then there's something he can't do: move that stone. Either way, there's something he can't do and so omnipotence is a chimera. Naturally again, there are plenty of counterarguments and countercounterarguments and countercountercounter . . . . etc. Regardless, the modal ontological argument is fascinating, not least because it makes denying God's existence much more problematic.

Wednesday, September 2, 2020

The Burden of Proof

It seems like everyone has a simplistic idea of who bears the burden of proof and it drives me freakin' nuts -- almost as much as people using "begs the question" to mean "forces us to ask."* The simplistic idea is that the person making a claim must bear the burden of proof, while the person who denies the claim does not. This is the standard in formal debates to keep them from going too far afield. Courts of law apply it as well because our justice system is premised on the "innocent until proven guilty" standard. So it's not unreasonable to mistake it as the universal standard, but it's still a mistake.

In philosophy burden of proof issues are notoriously difficult. Sometimes the person making a claim bears the burden of proof, but sometimes the person denying a claim bears it. Sometimes all parties bear it. It depends. And there's no absolute standard agreed upon by philosophers, although there are some clear examples. One traditional philosophical issue is the problem of other minds. How do we know that other people are really sparks of self-consciousness? The simplistic idea of burden of proof would say the person who denies other minds exist (solipsism) does not shoulder any of the burden of proof, but in this case he shoulders all of it. The person who affirms that other minds exist does not need to prove anything.

One objection people raise is that you can't prove a negative. Except you can. Of course you can. I can prove there is no full-sized elephant in this room right now. I can prove that there is not an army of fifty foot tall badgers ransacking downtown Portland as we speak. In fact, Karl Popper's philosophy of science says that all science can do is falsify claims, not prove them, in which case, science only proves negatives. It can't prove the positive claim "All swans are white" but it can prove the negative claim "Not all swans are white" by finding one example of a swan that isn't white. What you cannot do is empirically prove a universal negative. But you can still empirically prove a non-universal negative (like "Not all swans are white") and you can logically prove a universal negative (if it's a logical contradiction).

Another objection people raise is Bertrand Russell's suggestion of a teapot orbiting the sun between Earth and Mars. The person making this claim shoulders the burden of proof because in the absence of any evidence or reason to think such a teapot exists, the rational response is to disbelieve it, not just to be agnostic about it. We don't need a reason to disbelieve it, since in the absence of evidence we don't shoulder any burden of proof. But we do have a reason to disbelieve it: it's completely ad hoc or contrived. The more ad hoc a suggestion is, the less likely it is true. The teapot apologist must provide evidence to overcome the ad hoc-ness of the claim. Contrast this with the problem of other minds: there the solipsist is making the ad hoc claim and so must bear the burden of proof.

Most claims end up somewhere in between orbiting teapots and other minds (orbiting minds?), meaning that burden of proof is difficult to establish. The more ad hoc a claim is, the larger the share of the burden of proof one has, and sometimes denying a claim is more ad hoc than affirming it, not least because denying some claims can have repercussions that are outrageous. Carl Sagan said, "Incredible claims require incredible evidence," which is also simplistic and false, but if we restate it as "Ad hoc claims require sufficient evidence to counter their ad hoc-ness" then it can be salvaged, although it may not work as well as an aphorism.

* Incidentally, "begs the question" means you're arguing in a circle. You are assuming (begging) what is at question. So if I said "Trump is the most honest President ever," and when you asked why I believe that, I said, "Trump said so, and the most honest President ever wouldn't lie about something like that," I would be begging the question. The question is whether Trump is honest and my reasoning assumes he is in order to conclude he is. It argues in a circle, it begs the question. I actually wrote about this on Quodlibeta back in the day.