> I think the claim "there exists an external reality" is more than merely implied; it is an essential assumption, at least, if the conclusions of the use of science mean anything at all.

frum is, of course, completely right on this point. I stand corrected -- it is indeed an essential assumption. I don't know why I wrote implied, but that was wrong.

> There is another assumption of this sort that are required by the scientific method to have meaning, namely, that the relation of cause to effect holds indefinitely.

I agree with some reservations. Practically speaking, this is an assumption we make regularly when practicing science. I'm not sure it's *needed* for science, though. See my thoughts below.

> Unfortunately, like the claim that the external world exists, the claim that the cause-effect relation holds is impossible to prove, and must be assumed. Reason cannot get us past this assumption (thus far). I say this only to point out that the scientific method, as useful as it is, contains within it assumptions that are as non-rational as some of the claims of religions or superstitions.

Again I agree, and I had this point in mind when I initially wrote about science implying the existence of an external, objective reality. At the same time, though, I find these claims to be a bit different from other non-rational claims. For starters, pretty much every belief system that has any purpose must also assume that an external reality exists. I grant that we can conceive, intellectually, of belief systems in which the opposite was assumed. I also grant that these contrived beliefs would be as deductively valid as our belief in the scientific method. Practically speaking, however, they're completely worthless and adhered to by almost nobody. While this doesn't disprove them (the entire quandry is that we can't prove or disprove most low-level assumptions about reality), I'm also not too concerned with them.

The belief that a relationship between cause and effect will hold, however, I believe is a higher level one than the assumption that an observable, external reality exists. We can now make observations about this reality. Indeed, humans have made a lot of observations about reality during recorded history. Is there any compelling evidence to suggest that the fundamental laws which govern reality have ever changed? I know of no instance in which cause and effect simply stopped working. Is it possible that they could? Sure. But there's no evidence to suggest they ever will, nor any conceivable mechanism by which they would. Occam's Razor suggests we treat it the idea that cause and effect will always be linked as more probable than the idea that they are not permanetly linked.

Consider what were to happen if they were to become unlinked. It would be pretty much impossible to understand anything about the universe, but I still think the scientific method would be your best bet. After all, who knows when they might sporadically start working again? A partial understanding of reality, it stands to reason, is better than none. This is why the scientific method is so useful.

> Furthermore, I think that Matthew might be getting at something, though it seems somewhat confused. While I agree with you that science is not itself a belief or belief system, it is true that people tend to form beliefs based on the results of science, or not, and call those beliefs "science". For many people, prefacing a contention with the words "Science shows" or "Science says" (whatever that means) is commonplace, and such beliefs often have the same character as religious or superstitious beliefs. This can happen especially with 'scientific' theories, which are really belief systems that purport to organize and explain the results of science. Many of these, not being science proper, are difficult to evaluate according to the scientific method because they are often broad, far-reaching, and removed from the phenomenon they are meant to explain or coordinate. At this level, the theory level, what is commonly called 'science' may be no more inherently reasonable or reasoned than the claims of astrologers. Usually they have a better basis, but not always, so it is worth keeping in mind.

frum, you've lost me. Could you provide some examples of specific theories widely held by trained scientists that are as inherently unreasonable as those of astrologers? I agree, of course, that there are misapplications of science all the time, but I can't help but feel the above paragraph paints the "scientific community" with an overly broad brush.

> See:) Not being pedantic here, as I agree with you through most of the past section, and with this statement. But it is good to recognise that cause and effect is an assumption; we have used it for so long that it is easy to forget its assumptive character.

Agreed.

> > I'll agree with your general point, but allow me to be more specific: anybody who refuses to allow evidence to alter their previously-held notions is dangerous. This is the fundamental beauty of science: it encourages us to constantly re-evaluate our beliefs.
>
> Eeep. I don't know how strong we should make this claim. I am supposing, of course, that you mean good evidence, that is, repeated and repeatable, and relevant observations. And that is as it should be.

Yes, I meant that. I should have been more explicit.

> There are, however, some realms where this is not always the case. As C.S. Lewis pointed out, constant reevaluation of our beliefs about persons might be entirely inappropriate. If my wife has promised to be faithful to our marriage, sexually and otherwise, and at some point I find that there is some, or even much, evidence that she has been unfaithful, I really would be a terrible person if I divorced her immediately. She might be innocent, in which case, time might tell, or perhaps I would need to trust her word alone. My wife may have been cheating on me. The relevant point is simply that between persons, the bounds of what is considered reasonable trust are significantly stretched, and it is often considered right and proper to trust even in the face of what 'seems' to be evidence of broken trust. This is what differentiates belief in God (in the judeo-christian sense) from coming to believe in God. In the former case, one has moved into a relationship very much like that with a person, and as such what one is willing to believe may go well beyond what would otherwise be irrational. When deciding whether God exists, however, one is in a quite different position, and the usual ruthlessness of the scientific method might be appropriate.

I can't really think to reply to all of this right now (it's nearly 3 a.m. and my head is pounding). frum's exact point here is also slightly lost on me. Let me tackle a few important points I see:

1) Constantly re-evaluating our beliefs about people is admittedly silly. I do think that we should be able to incorporate new evidence about a person into our view of that person without re-evaluating all of our beliefs about that person. Strong evidence that suggests the person is radically different than we thought, however, should probably require us to rethink our views on that person.

If the cops show me three people who saw my friend Tom leaving the scene of a murder shortly after it happened, and they show me the gun used to commit the murder was Tom's and had his fingerprints on it, you can be damned sure I'm going to re-evaluate my friendship with Tom. There's no direct evidence that he's a murderer, and he may have had justifiable reasons for doing it if he did. I'm still going to be uncomfortable around him. This is smart. It would not be smart to ignore the evidence and say, "Well, I've known him in the past and he'd never do something like that."

2) As frum points out, trust can be stretched. But this requires us to be suspicious. If I suspect my wife is having an affair, it would be bad to divorce her. But it would be smart to be more observant to her behavior now, to look for clues, etc. This is in some way a reevaluation of my beliefs about her. I'm not saying that we need to throw out our beliefs the instant some contrary evidence comes along, but we should be willing to temper our beliefs and perhaps apply the sword of skepticism to them a bit more liberally than normal when contradicting evidence turns up.

3) I think I agree on the God thing, assuming I'm reading it right. Having yet to find proof for God's existence, though, I am still in the latter category of people. I do hope that were I to be religious, I would still examine and be skeptical about my religious beliefs. Again, this doesn't mean abandoning them every time I see what appears to be contradicting evidence, but that I'm willing to modify them when good, repeatable evidence becomes known to me.

Stephen