Showing posts with label rationality. Show all posts
Showing posts with label rationality. Show all posts

Tuesday, April 6, 2010

Positivism 101

The philosophy underlying the sciences is known as "logical positivism", and was first codified around the turn of the 20th century. At its core is a fairly simple, obvious epistemology that permits metaphysical and ethical questions to be ignored entirely, freeing the sciences to concentrate on the questions the scientific method can actually work on.

The basics of positivist epistemology are simple: All statements are either positive or normative (we'll ignore for now the possibility of completely nonsensical statements). A positive statement is a statement about the empirically measurable properties of one or more physical entities. For example, "This camel has three humps," is a positive statement, because the camel is a physical entity, and its number of humps is an empirically measurable property. "No camels have three humps," is also a positive statement; it speaks about the same empirically measurable property of a large number of different physical entities, the camels.

A positive statement can be either true or false, and indeed all positive statements are one of the two (though we can't always know which). For example, though we can never know how many times George Washington blinked on April 26, 1780, there is a correct answer to the question. George Washington is a physical entity, and the number of times he blinked is empirically measurable. Each of his blinks had an impact on the world around him -- for example, by creating tiny air currents -- and in theory, given infinitely accurate measuring devices, unlimited computing power and speed, and the right theoretical models, we could reconstruct his blinks on that day.

Sometimes a statement can be defined as positive not because it is itself about the empirically measurable properties about a physical object, but rather because it has logically necessary consequences which are positive statements. For example, the claim that a physical object exists is a positive claim because, although existence itself is not an empirically measurable property, in order for a physical object to exist it must have certain properties. For example, Russell's teapot is a hypothetical that claims that there exists a small china teapot suspended exactly opposite from the Earth in the same orbit, so that the Sun is always between us and it. If the claim is true, then the teapot, as a physical object, must have mass; this is an empirically measurable property. Thus, Russell's teapot is a positive claim.

Claims which are not positive are normative. An example of a normative claim is, "Eating kittens is wrong." Eating a kitten is a physical event, but "wrongness" is not an empirically measurable property. Normative statements are too dependent on the speaker to have a truth value; I might find eating kittens to be wrong, but you might not, despite no change in the physical event.

Any normative statement can be turned into a positive statement about Bob by adding "Bob says that..." to it. (Substitute the speaker of your choice for Bob.) For example, "Eating kittens is wrong," is a normative statement about eating kittens. "Bob says that eating kittens is wrong," is a positive statement about Bob. We can take empirical measurements (for example, asking Bob and listening to his response) to determine if this claim about Bob is true.

Some people argue that experiences such as "wrongness" or "the numinous" or "freedom" are empirical phenomena because they correspond to particular states of the brain. While probably true (certainly there is no evidence to suggest that any state of mind is anything other than a state of the brain), this is really only a variant of adding "Bob says that..." "This brain responds to kitten-eating by firing the wrongness neurons," is a statement about a particular brain; it still does not point to any inherent properties of kitten-eating.

As I mentioned above, normative statements cannot be regarded as "true" because they depend too much on the speaker. They qualitatively differ from untestable positive claims like George Washington's blinking: Even given unlimited measuring equipment and infinite computational power, I cannot detect a physical property of wrongness or justice or value because there is no such thing. The most I can accomplish is some version of "Bob says that..." There is no correct answer to the kitten-eating question, only opinions.

If no normative statement can be true, then no normative statement can be false. If a normative statement were false, then its negation would be true. For example, if we declare "Eating kittens is wrong," to be false, then we're saying "Eating kittens is not wrong," is true. But that statement is also a normative statement, and therefore cannot be true. Thus, we must conclude that normative statements have no truth value.

The founders of logical positivism went further, and declared normative statements to be meaningless. From a purely scientific perspective, that's true: science cannot work with or generate normative statements, and it's dangerous to try. From any other perspective, however, that's nonsense. Linguistically, culturally, neurologically, normative statements absolutely do have meaning -- I'd like to see someone try to get through a day without acting as if value is a meaningful concept! -- and so, except when we are considering scientific questions, it would be foolish to dismiss normative statements just for being normative.

Let's put this another way. A statement is true if it accurately models our physical reality. It is false if it contradicts physical reality. All true statements and all false statements together make up the set of positive statements; hence, all positive statements are attempts to model physical reality and vice versa. A statement which does not model physical reality is normative; since it neither accurately models nor contradicts physical reality, it is neither true nor false.

Claims of existence are a somewhat tricky case. The problem is that most people are not philosophically rigorous, and hence language is not, either. So, for example, when Russell claims his teapot exists, he is claiming that it physically exists and therefore has physical properties, such as mass and position. When someone claims that love exists, however, they are generally not saying that there is a substance called "love" that physically exists and can be detected; rather, they are saying that a particular pattern of behavior occurs in human relations. This is still a positive claim -- human behavior can be empirically observed and recorded, and we can see if it's consistent with the love hypothesis or not.

However, when someone claims that free will exists, they are using a different definition still. They are not (generally speaking) claiming that there is a "free will" substance with physical properties. Nor is the claim that free will exists something that can be tested by observing human behavior; human behavior is exactly the same whether it is caused by deterministic, but highly complex and impossible to predict, natural phenomena or free choices that "hide" in the "highly complex and impossible to predict" part. There are, in fact, no statements about physical phenomena that follow logically from "Free will exists"; thus, it is not a positive statement.

Similarly, one could claim that a teapot exists in another universe, entirely distinct from our own. Since there is no attempt here to model physical reality -- we are talking about some other, purely hypothetical, reality -- the claim is entirely normative. Depending on the context in which the claim is made and how seriously we are expected to take it, we might call such a statement fiction, myth, allegory, a thought experiment, a parable, or any of a hundred other related concepts.

So, we come to the big one: "God exists." Is this a positive or normative statement? Well, it mostly depends on what you mean by "God." If you're an animist and believe that the universe has a guiding spirit akin to the human will, that's not a positive claim any more than free will is. If you're a Christian and mean that a first-century rabbi healed sick people, revived the dead, preached, died, came back from the dead, and then left this universe (reducing its total mass-energy by a hundred kilos or so), that's very much a positive claim.

A universe in which Jesus came back from the dead is different from one in which Jesus did not come back from the dead. Given the right equipment, we could measure the universe and determine which occurred. This is not a matter of opinion; it happened or it didn't. I think it didn't, but even if we could prove it didn't, most Christians would adjust just fine. They've already adapted (except for a few vocal nutters) to viewing their creation myth in metaphorical terms, once its positive claims were shown to be false. There's no reason they couldn't do the same with their main hero-cycle myth, as well.

Most religious people, like most people, don't particularly care much about modeling physical reality. Most religious people are just fine to say "Leave it to the scientists to work out how the universe functions; God is why." Just as free will has no impact on human behavior, and thus is not a positive statement, so does the existence of this sort of God have no impact on the behavior of the physical universe. Such a God is not a positive claim. There is no difference between a universe with such a God and a universe without such a God; they are the same universe.

Since they are the same universe, neither the believer nor the atheist can be right or wrong. There are no competing models of physical reality here; only two different ways of looking at the same physical reality. Reason does not compel a position on the question; we are free to believe as we choose.

Friday, November 20, 2009

It's Rational to Be Irrational (Sometimes)

A little thought experiment that will help lay the groundwork for later posts:

A rational being is one which always acts to maximize the likelihood of producing optimal outcomes. In other words: A rational being has some set of pre-rational preferences, and a body of available information. Using this information, the rational being evaluates the available courses of action and chooses the one that appears likeliest to produce the most-preferred (optimal) outcome.

We thus already see that a rational being cannot exist without something irrational, namely preferences. But there's a deeper way in which irrationality can be rational.

Imagine that you are in the jungle. You, like all human beings, have a capacity called agency attribution. This is, effectively, an alarm system that notifies you when a sensory input is caused by an intentional act. In other words, it's what distinguishes between leaves rustled by the wind (non-intentional), and leaves rustled by a hungry tiger stalking you (intentional). If you were perfectly rational, you would assign agency wherever there was evidence of an intentional being, and no other time.

However, here in the jungle, tigers are pretty good at hiding. There's a good likelihood that those rustling leaves are a tiger, even though there's no evidence that it's anything other than the wind. If you fearfully and irrationally shoot at every rustling leaf, on the knee-jerk assumption that it's a tiger, you are likelier to survive than if you're purely rational about it.

Increasing your survival chances is, generally, a pretty rational thing to do. So, in this circumstance, behaving irrationally on one level is actually rational on a higher level (meta-rational?) Indeed, I'd speculate that something like this scenario creates a selection pressure for a hair-trigger agency attribution, which would explain why it's a nigh-universal human trait.

Anyway, if this scenario seems oddly familiar, it should be: it's Pascal's Wager, only with a tiger instead of a vengeful God. I'm not arguing that Pascal's Wager should be regarded as a valid argument for belief in God (the difference is that tigers can be demonstrated to exist); only that the kind of irrationality which leads to Pascal's Wager serves a useful function.

Edit for Clarity: What I am arguing, in essence, is that there are circumstances under which a hypothetical, fully rational being, who prefers survival to death, will wish to be less rational. To put this yet another way: there exist selection pressures favoring certain forms of irrationality.

Monday, October 26, 2009

Unburdened

One of my purposes in starting this blog has been to serve as a counterpoint to some of the atheists you tend to encounter online. You know the ones I'm talking about, I'm sure -- running around insisting religion is stupid and irrational, demanding that religious people prove God exists, and generally proving that fundamentalist Christianity by no means has a monopoly on assholes.

Part of my plan is a series of posts dealing with the serious flaws in standard Internet Atheist arguments. For this inaugural post, we'll talk about the burden of proof.

(Note: When I refer to God with a capital "G", I'm talking about a transcendent, omnipotent, omniscient creator which is also a person. I also intend the term to include sets of persons who have those properties when considered collectively, for example some views on the Hindu pantheon. I use the male singular pronoun to refer to God, because that's the tradition used by most people who believe in such a God. I am well aware that not every religious person believes in a singular, personal, masculine, transcendent divinity, and that any given tradition may reject one or all of those descriptors. No offense is intended or, I hope, taken. Please bear with me for the sake of argument.)

The concept of burden of proof, as used by Internet Atheists, has to do with competing claims about existence. Imagine, for example, that I claim there is such a thing as a three-humped camel. You claim there is no such thing. Obviously, only one of these claims can be true.

If there is such a thing as a three-humped camel, then I can prove it by producing the camel. On the other hand, if there is no such thing as a three-humped camel, the only way to prove it is to examine every camel in the world. Quite a difficult task! So, my claim is easier to test, and the burden of proof thus falls on me. In the absence of evidence for a three-humped camel, it's best to assume there is probably no such thing.

This may seem counterintuitive: the easier claim to prove is the one you assume is false. However, it makes sense if you think about it. Since, if true, my claim is so much easier to prove, the fact that I haven't proven it is suspicious. In general, claims that something exists are easier to prove than claims that it does not: to prove it exists, you just have to produce it, but to prove it does not requires searching the entire universe. Hence the rule of thumb that the burden of proof lies with the person making the positive claim of existence. Closely related is the claim "It's impossible to prove a negative." You can't prove that three-humped camels don't exist, because there's always the possibility that you missed the one camel that does have three humps.

If you stop there, it might seem like the Internet atheists have a point: doesn't the burden of proof rest on the person making the claim that God exists?

Well... not always. Remember, the only reason the burden of proof rests on the person claiming three-humped camels exist is because that is the easier claim to prove. In the case of God... well, how exactly would you go about proving that God exists? People have been trying for centuries, and consistently failed. God is neither logically necessary (there is nothing known about the universe which could not be true if God did not exist) nor empirically detectable. There is no device or experiment that can detect an omnipotent being if it doesn't want to be found, nor is there any way to be sure that an apparent miracle is not actually a perfectly natural phenomenon we simply haven't figured out yet.

What about disproving God? Again, you can't. It's not just a matter of checking every camel in the world -- here we're dealing with a three-humped camel that can look two-humped whenever it wants to. The way God is defined makes it impossible to disprove.

So, both claims are impossible to prove, and thus equally (infinitely) difficult to prove. Neither claim carries the burden of proof.

What does that mean? Well, with the camels, in the absence of evidence either way, it is more rational to disbelieve in the three-humped camel, because there should be evidence of it if it's true. That doesn't apply to God. In the absence of evidence either way, and all other things being equal, it is not more rational to disbelieve in the existence of God, nor is it more rational to believe in the existence of God. Both claims are equally (ir)rational.