While measuring the depth of Walden Pond, Thoreau noticed that the point of greatest depth lay exactly at the intersection of the pond’s greatest length and its greatest width. Intrigued, he began to wonder. “I said to myself, Who knows but this hint would conduct to the deepest part of the ocean as well as of a pond or puddle? Is not this the rule also for the height of mountains, regarded as the opposite of valleys? We know that a hill is not highest at its narrowest part.”
While he never fully resolved the question, he took preliminary steps to test it. Ecologist Daniel Botkin wrote a fascinating article about this, “Henry David Thoreau and the Depth of Walden Pond.” (adapted from his book, No Man’s Garden)
In it, Botkin explains how Thoreau’s work is a good example of using a scientific approach to answer questions. The entire piece is worth reading and goes into some of Henry’s other projects that aren’t covered in Walden, but here I will quote only the opening paragraphs:
“During the time that I have been an ecological scientist and involved with environmental issues, I have found several ironies of our modern technological and scientific information age. The first irony is that often we do not measure what we need to know. I have been involved in a lot of major environmental issues, from the conservation of bowhead and sperm whales to the possible effects of global warming on forests. In each case I find that there are key pieces of information missing that nobody has bothered to find out.
“The second irony of the information age thing is that, if we do measure something useful, we usually don’t bother to use it. This is true among scientists as well as among public agencies and non-profit interest groups. We just archive information and forget it.
“The third irony that, although we have the ability to gather many kinds of scientific information, we tend to solve environmental problems from ancient myths, plausibilities, false inferences, and ideologies. This means we often start with an answer that we wish were true and squeeze whatever scientific information we use into a mold that conforms to this wish. And we get very upset if people do not believe us.”
Thoreau understood the importance of gathering good data and testing one’s hypotheses. In this way he was confident that we could uncover the laws of nature. And then, he says, “If we knew all the laws of Nature, we should need only one fact, or the description of one actual phenomenon, to infer all the particular results at that point. Now we know only a few laws, and our result is vitiated, not, of course, by any confusion or irregularity in Nature, but by our ignorance of essential elements in the calculation.”
This is a grand vision, shared today by scientists who are hopeful of a “theory of everything.” But watch out. No sooner does Henry say this than he begins to speculate.
“What I have observed of the pond is no less true in ethics… Perhaps we need only to know how [a man’s] shores trend and his adjacent country or circumstances, to infer his depth and concealed bottom. If he is surrounded by mountainous circumstances, an Achillean shore, whose peaks overshadow and are reflected in his bosom, they suggest a corresponding depth in him… In our bodies, a bold projecting brow falls off to and indicates a corresponding depth of thought…”
Whoops. In his enthusiasm for analogies, he has wandered off into the realm of phrenology, a popular idea of the day that proposed that you could infer intelligence and personality from the shape of a person’s skull. Phrenology claimed to be a science, but in the end science proved to be its undoing.
Thoreau wasn’t really doing anything wrong here. Speculating, making connections, guessing how your data might apply to other circumstances, imagining what general principles might lurk behind your particular results — this is all part of science… but the trick is, you don’t stop there. You can engage in wild-ass speculation to your heart’s content, but then you figure out how to put it to the test. After that, some ideas will look even more plausible, and others will look just as silly as the notion of a bottomless pond.
(About “A Year in Walden”)