At the end of last week's blog entry, I made a statement that I suspect some people will find controversial: science is the only source we have of genuinely reliable information; there is no other.

If there is another reasonably reliable road to truth, I haven't noticed it. Think you've got one? I'm all ears.

Some people depend on faith, ^Note 1 about which the brilliant Bertrand Russell said:

But for every born-again Christian whose deep faith in Jesus allows for no other truth, there's a Muslim fundamentalist whose deep (and on significant points contradictory) faith is no less the sole truth. And those are only two widely held religious points of view. There are hundreds of others. In other words, different people have faith in different things, often at odds with one another.

And who has faith in what? Isn't it clear that people from a Christian background tend to develop Christian faith, while people born into heavily Muslim countries tend to develop faith in Islam? There are exceptions, of course, but on the whole, most people develop faith in precisely what they were taught at their mother's knee.

Besides, your faith represents not one iota of evidence for me. I don't have faith, and someone else's faith is not evidence for me. Nor is the strength of one's faith evidence for its truth. Over many centuries, many people have given their lives for various contradictory faiths.

Here's another test of faith. Suppose I told you that I believe that the universe was created by the Flying Spaghetti Monster (see right), making me a Pastafarian. You might ask how I could believe such a silly thing. If I were to answer, "I believe it on faith!", would you then reply, "Oh, well then, that's perfectly reasonable"?

When it's put that way, I think most people realize that faith is not a valid argument for anything. It's just a license to accept any idea that appeals to you.

Some people argue that truth can be found in other forms of deeply held feelings. No matter what it's called, the arguments against accepting things on faith apply equally. Where's the connection to reality?

Similarly, some argue that firm knowledge can be obtained through personal experience, "It works for me." This even sounds a bit like science - it's empirical observation, after all. But having come to better understand the scientific method, I now look at personal experience a bit differently. A personal experience is a scientific experiment with N=1 ("N" being the number of subjects), and no control group. It's not double-blind, and it's not even single-blind. Furthermore, the experimenter is the most biased possible observer you could find on the face of the earth, namely the same person as the experimental subject.

In other words, a personal experience is a bad experiment - scientists might call it an "anecdotal" experiment. Almost nothing is more subject to error and self-deception than personal experience, despite the fact that personal experience feels very compelling to people. There are occasionally automobile accidents in which a driver or passenger is saved by being thrown free of the car, when he or she might have been killed or seriously injured by being trapped by a seatbelt. When a person has had such an accident, or knows someone who has had such an accident, they will frequently never wear a seatbelt again.

But that's a bad decision. Such accidents are rare, and when a driver or passenger is thrown out of a car during an accident, the result is most often fatal. A driver who survives such an accident without a seatbelt has simply had a lucky good outcome after making a bad decision. ^Note 2 

There's a common source of bias that occurs so frequently that it has a Latin name, "Post hoc ergo propter hoc", which means, "It follows, therefore it was caused by." One will often hear someone say something like, "Taking Motrin relieved my back pain." Well, perhaps it did, but back pain often resolves itself over time without any medication. Perhaps the Motrin had nothing to do with it.

Often, people with personal experience are utterly sure of themselves, so strong does it feel. Women who had gotten breast implants and subsequently came down with auto-immune disease were utterly certain that leaking implants had caused the disease. Parents of autistic children were absolutely sure that the problem had been caused by mercury in vaccines. Both of these connections proved illusory after the science was done.

What I'm after is truth. As Jesus allegedly said, "You shall know the truth, and the truth shall set you free." So having quoted Jesus, what about revelation as a road to truth? Many claim the truth has been handed to us by God, in a book. However, the question then is, "Which book?". For Christians, it's the Judeo-Christian Bible, but for Muslims, it's the Koran.

There are thousands of web pages claiming that the Bible is a remarkable book which is error-free, and couldn't possibly have been written by ordinary humans. But additional searching on the Internet reveals many similar web pages that make the same claim about the Koran. I'm sure there are other books thought to be revelations from God - I see no reason to take any of these "revelations" seriously.

There are forms of revelation other than books. Many people over history have claimed to receive direct communication from God in various ways. As with faith, your claimed revelation is not evidence to me.

Some might ask, why is science any better? I noted above that different versions of faith can lead to contradictory answers, tending to indicate that faith is an unreliable source of truth. But science makes errors too. Scientists are human beings, and they make mistakes. Furthermore, as I pointed out in my last blog entry on science, science is difficult to do.

The idea of continental drift, for example, was once considered to be ridiculous. It's now accepted as confirmed. In my previous blog entry I mentioned several other errors made by scientists, such as polywater and cold fusion. Scientists learned from these over the centuries, and adjusted the scientific method to contain elaborate safeguards against self-deception. That's why Richard Feynman concisely defined science as, "A way of not fooling yourself".

So science isn't foolproof, either. But science has a methodology, a process, for converging on the truth over time. Experiments are repeated, by different researchers, using different experimental protocols. Papers describing research are peer-reviewed in reputable journals to weed out potential problems. Over time, science has a process for eventually correcting errors. Sometimes it takes centuries. But it's the best we have.

I might add that science has a way of developing methods to study things that once seemed entirely out of its reach. As a graduate student at MIT, I considered doing research on the operation of the human brain. I talked with Prof. Jerome Lettvin, who had figured out neural coding in the frog's optic nerve, described in his seminal paper, "What the frog's eye tells the frog's brain". ^Note 3

But he discouraged me from entering the field, because he didn't think the tools available at the time made study of the brain possible. Now, decades later, we have things like functional MRI (Magnetic Resonance Imaging) and PET scans (Positron Emission Tomography), and progress is being made in understanding the brain that would have been unthinkable when I considered addressing the problem.

Nevertheless, there's an awful lot that science is currently incapable of studying, and there are probably many things that science will never be able to understand. In particular, there are many important questions about human beings that could only be answered by doing experiments that are entirely unethical. For example, isolating a baby from all human language to see what happens has been called the "forbidden experiment". There are an enormous number of important questions that cannot currently be answered by science, and some of them may never be answered.

To which I reply, "And your point is?".

Pardon the sarcasm, but do people think the universe owes them an answer to every question? In particular, the implication that since science can't answer every question, there must therefore be another way to get the answer, is completely illogical. There's an awful lot we don't know (Thomas Edison once said, "We don't know one millionth of one percent about anything"). The human race will probably come and go without ever finding out the answer to a great many questions. Grow up. Get over it. W. Somerset Maugham once said, "It wasn't until extremely late in life that I learned how easy it is to say, 'I don't know'."

Finally, it's been said that in the end, whatever anyone believes is ultimately based on faith. I've been told that while I might discount someone else's religious faith, my own belief in science can only be based on faith. Science, in a way, is my religion.

I don't think that's true. I don't "believe in science" by faith. I use the scientific method because it works. Science is a systematized form of empiricism - learning about the world by observing it (carefully). And empirically, empiricism works. This seems like a circular argument, but what would you have me do, lean on something that doesn't work? In a sense, empiricism is its own reward.

Scientists act as if the physical "laws" they discover will remain valid forever (these are really "descriptions" not "laws" as in the legal sense). But scientists don't "believe" this by faith, rather this has just been true in the past. If next Tuesday, the mass of the electron suddenly were to change by ten percent, we'd feel the effect immediately. It might take scientists several years to figure out what had happened, because nothing like this has ever happened before, and it would be the last thing to suspect. But eventually they'd come around.

They'd throw up their hands, moan and groan, and set out to find the new mass, and to understand the consequences of the change. What I'm trying to point out is that scientists don't accept science on faith at all. They simply use it because it works (at least so far).

By the way, if the mass of the electron changed by ten percent, we'd feel the effect immediately because every computer, every cell phone, every television, every radio, everything electronic would immediately cease to operate. The best indications that science produces an accurate description of the world are the products of engineering.

I'm not a scientist myself, I'm an engineer. But I like to think that makes me an "applied scientist". The fact that the things designed by me and other engineers actually work is a testament to the accuracy of the truths discovered by science.

So that's why I think that science is in fact the only road to truth. If you think you've got others, please do let me know. We can use all the help we can get.
 

Note 1:   I'm using the word "faith" in what I think of as the usual religious sense. Obviously, the word has a lot of more commonplace meanings, as in "I have faith that my wife will take care of me if I get sick."   [return to text]

Note 2:   The important distinction between a good or bad decision versus a good or bad outcome was discussed in my blog entry entitled "The gambler". I've previously mentioned this in my blog entry Live Free and Die.   [return to text]

Note 3:   Lettvin, J.Y; Maturana, H.R.; McCulloch, W.S.; Pitts, W.H., What the frog's eye tells the frog's brain, Proceedings of the IRE, Vol. 47, No. 11, November 1959   [return to text]