Saturday, November 12, 2011

Why Change Your Mind?

Suppose I have some belief. Under what circumstances should I change it?

A common atheist response is that we should reject any belief for which we don't have evidence.  Graham Oppy calls this "Clifford's principle." Oppy thinks it's untenable.

Oppy starts off his book with a discusion of beliefs and their formation and revision. He approves of Harman's Principle of Conservatism:

One is justified in continuing to fully accept something in the absence of special reason not to.

Specifically, Harman says I shouldn't change my mind simply because my belief is not adequately justified (denial of the Principle of Negative Undermining). But I should change my mind if I have positive reasons for thinking my belief is no good (the Principle of Positive Undermining).

Oppy doesn't go into great detail on these principles, but I think what he is getting at is something like the following. We each have a complex network of interlocking beliefs. Many of these beliefs have never been critically examined (by me), and hence aren't adequately justified. For example, I believe Minsk is a city in Russia. I have never been to Russia, let alone Minsk, nor have I ever met anyone from there. I probably learned about Minsk from a book or a casual conversation, or possibly in school. According to Oppy, I should go on believing this, even though I do not have adequate justification. If someone comes along and says, "Minsk isn't in Russia, you idiot, it's the capital of Belarus!" or if I bother to look it up in an atlas, then I have reason to change my belief.

Most of our beliefs are like this. I believe a squirrel is a mammal, even though I have never seen one suckle its young. I believe water is composed of hydrogen and oxygen, even though I have never performed an experiment to prove this. I believe my father was born in Philadelphia, even though I have never seen his birth certificate. And so forth.

In this view, the atheist who says, "I never believe anything unless I have evidence for it" is saying something profoundly stupid. Such a principle would require a retreat to near total skepticism.

Oppy's position here is a sophisticated version of the religionist who says, "But you have faith, too!" And I think he's right. If "faith" means "belief without adequate supporting reasons," then we all have to have faith. Life is simply too short to completely, or even adequately, examine all of our beliefs.

This helps us understand why so many people have irrational beliefs, and why they are so hard to change. It is actually better (in an evolutionary sense) to continue to believe unsupported things than to jettison too many beliefs and be paralyzed into inaction. It may be that something like the Principle of Conservatism is built into our psychological makeup to prevent this kind of paralysis.


  1. I have a few problems with your reasoning.

    1) Very few Atheists say they never believe ANYTHING without evidence for it. As you pointed out, that would be ridiculous. I think it bears mentioning that Atheists do not, by and large, treat the requirement for evidence as the all encompassing lifestyle that you suggest they might.

    2) Your analogy involving the city of Minsk is somewhat misapplied to the question of religion, which is what is really at the heart of your article. In the case of Minsk, i have not yet acquired the evidence needed to assert with certainty that it exists and is what i think it is. But I could if i were so inclined. With religion there is no way to acquire that evidence. Atheists realize this and recognize it for the telling reality that it is. When there is no evidence for something, and those who still believe in it freely admit that acquiring such evidence is impossible then there is sufficient reason to completely dismiss their claims. When an atheist says "I don't and wont believe without evidence" that is what they mean.

    3) Building on my second point, when a theist claims that Atheists take things on faith because we accept things we don't have sufficient evidence to accept, a silly amalgamation of terminology and ideas is created. To take some provable but not yet proven idea to be true is not the same as taking some improvable and nonsensical idea to be true. One is a provisional acceptance without yet having acquired evidence. The other is full and uncritical acceptance of a fantastical idea without any requirement or interest in evidence to support it or, worse, in spite of evidence to the contrary.

  2. Nonsensei:

    Thanks for your comment. Unfortunately, one does often hear atheists assert such things. A recent example was a video clip of an Australian skeptic who spoke out on a TV show and was applauded by the atheist blogs.

    2&3) I don't think most theists would agree that they believe without evidence, or that they believe even though it is impossible to gather relevant evidence. Rather, they see things as fine tuning or the universe itself as evidence for God. Likewise, theists would not agree that theism is "nonsensical." (I know some atheists have tried to show that the concept of God is incoherent, but it is not generally accepted, even by atheists, that they have been successful.)

    This is not to deny that there are significant differences between the Minsk example and religion. If I want to visit Minsk, I better exert myself to learn more about it, at least to the extent of what country it's in. At that point, its existence and location become relevant to my life in a way that requires more than casual and unthinking belief.

    With religion, if one is to center one's life around it, it is already relevant to one's life, and one shouldn't take such a casual approach to it.