Knowing by faith

There is a common line of argument that says there are "other ways of knowing", and science can't tell you everything. Usually this is intended to counter a perceived lack of evidence for some supernatural belief or other, and usually it will cite either Godel's incompleteness theorem or some strong emotion like "love".

I have never seen such an argument that actually cited a piece of knowledge that is genuinely obtained other than by science (or some broadly similar approach), or mathematics (which is not about the real world until science connects the two).

Recently I ran into it yet again in a piece by Mehdi Hasan. Apart from trying to confuse "evidence" and "proof" (here's a tip for Mehdi: science doesn't prove anything, and doesn't claim to except in the sense of testing), he says that "...there are plenty of things that cannot be scientifically tested or proven but that we believe to be true, reasonable, obvious even." He gives some examples, all of which illustrate my claim.

"Which of these four pretty uncontroversial statements is scientifically testable? 1) Your spouse loves you. 2) The Taj Mahal is beautiful. 3) There are conscious minds other than your own. 4) The Nazis were evil." Taking these in order:

1) You can test this by formulating hypotheses of expected behavior, and comparing your spouse's actual behavior. Most people do. The word "spouse" implies some sort of commitment ceremony; there are major life adjustments, conversations, etc. Some of these might be evidence against; perhaps it's an arranged marriage, or an immigration scam. Perhaps there's been an affair, or perhaps they looked after you when you were broke. It's a tricky question - do you mean now, on average, on balance? How much love qualifies? What kind? For that matter, there are no doubt many people out there who know their spouse doesn't love them. This is far from uncontroversial. Science is improving in this area; one day we might be able to get a fairly useful answer with an MRI machine. 

None of this is helped by religious-style faith. You can't pray and find out an answer, or a lot of disastrous marriages might be avoided. And having faith without evidence that somebody loves you is often a good way to get a court order against you.

2) You investigate this scientifically the same way that Mehdi did - beauty is a subjective question, and something is beautiful if enough people think it is. What do people do with beautiful things? They visit them to look, and they report that they find them beautiful. So it is with the Taj Mahal. We have no need to take it on faith.

3) Once I have figured out what it means to be conscious, I can look for the signs in those around me. Most people accumulate sufficient evidence in early childhood. Indeed, a failure to do so is considered a clear-cut symptom of developmental problems. They don't do so by faith; they do so by overwhelming evidence. Later they can discover the science that shows their brains work the same way as everyone else's.

4) There's an enormous body of historical evidence documenting what the Nazis did and why. I'm certainly including such efforts in my definition of science. "Evil" is a more nebulous concept, but most people have no trouble applying it to mass murder. And there is plenty of evidence of choices taken where a good society would do one thing and the Nazis did another.

Faith, on the other hand, is more likely to get you into the land of conspiracy theories, of which there have been many over the years.

I am still waiting for some piece of knowledge that we can have without the testing of evidence. Mehdi's effort goes nowhere in this regard. Indeed, the people who think there is another way are never able to agree amongst themselves what that knowledge might be. Hence the huge variety of religions I see around me. That, to me, is evidence that they have not yet found another source.