Science, knowledge, and the Little Engine that Could

The tale of The Little Engine that Could remains a perennial classic of early children's literature, and understandably so. The story (which we all know, so why am I bothering to repeat it?) involves a little blue engine commissioned with the task of pulling a large train over a very large hill. Initially success appears impossible as the little engine begins chugging up the steep grade, all the while repeating the hopeful mantra "I think I can, I think I can". Then success appears improbable as he rises higher up the hill, still chanting the hope. Then success appears not likely as he rises higher still. And then as he crests the hill, "I think I can" morphs into a triumphant "I know I can!" And with that he picks up increasing speed, as children the world over clap their hands in delight and warm fuzzy feelings abound.

The moral of the tale is clear. A positive can-do attitude can accomplish great results. And even if it doesn't guarantee you'll crest every hill, it certainly makes it more likely.

But there are limits. The Little Engine that attempts to scale Everest or K2 doesn't look brave. He just looks foolhardy. By looking at the little blue train, and then back at the Himalayas, one can see that a successful ascent is, in this case, clearly impossible.

What if somebody disagreed? Let's call him Bo Duke (in recognition of John Schneider's stellar work on "The Dukes of Hazzard). So Bo Duke counters: "I will grant that I cannot see how the Little Engine could scale Everest, but that doesn't mean I can see that he can't. Maybe he can, even though I cannot presently see how."

This is an interesting point of disagreement between Bo Duke and I. But what exactly is the point, you ask?

The point is that our disagreement parallels a very deep disagreement between two groups: those who think that science in principle has limits and those who deny that science has limits.

The little engine is science. Everybody can agree that science has scaled some incredibly high mountains. One thinks, for instance, of the scientists working on the Human Genome Project, chanting "We think we can" for hour after hour, day after day, year after year, until 2003 when they completed that milestone of mapping the entire genome. Such examples provide ready evidence that science can scale a good many mountains.

But innumerable mountains remain, mountains that have traditionally been considered the domain of theology and philosophy. Among these are the mountain of consciousness, the mountain of free will, the mountain of ethics, the mountain of aesthetics, and the mountain of rationality and knowledge.

In each of these cases there have been those who have argued that even if we cannot see how that cheeky little engine which just mapped the human genome can explain everything from consciousness to ethics, we are justified in concluding that one day it will. (E.O. Wilson's Consilience is a classic statement of this view.)

On the other hand, there are those who believe we understand enough of these realities to know that science can never, in principle, scale these peaks. On this view the little engine might as well turn around and go back to the roundhouse.

So who is right? Does science have limits in principle or not? How can we know?