In 2001, I was asked to give the Keynote address to the annual meeting of the Henry David Thoreau Society. The talk, based on my book, No Man’s Garden, was published in The Concord Saunterer, the publication of the Thoreau Society. Here is an except from it.
Ironies of the Information Age
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 as a Seeker of Quantitative Information
Here Thoreau is a wonderful example to us. Thoreau buffs are familiar with his search for quantitative measurements, his careful analysis of information, and how his imagination was stimulated by what he learned. His experience that strikes me the strongest is his measurement of the depth of Walden Pond.
"There have been many stories about the bottom, or rather no bottom, of this pond, which certainly had no foundation for themselves," Thoreau punned in Walden. "It is remarkable how long men will believe in the bottomlessness of a pond without taking the trouble to sound it."' He went on to write that "Many have believed that Walden reached quite through to the other side of the globe" (285). And so he became interested in the depth of the pond and set out to learn this physical, quantitative characteristic of one of his favorite places in nature.
As a person with an intrinsic naturalist's and observer's inclination, Thoreau took a simple and direct approach to determining the depth of the pond: he measured it. He had the skill to do this, because he often worked as a surveyor. "As I was desirous to recover the long lost bottom of Walden Pond," he wrote, "I surveyed it carefully, before the ice broke up early in '46 with compass and chain and sounding line. I fathomed it easily with a cod-line and a stone weighing about a pound and a half, and could tell accurately when the stone left the bottom, by having to pull so much harder before the water got underneath to help me" (285-287). Thoreau made an important step from informal natural history to quantitative measurement. This is a key step in using science to obtain a new kind of understanding of nature.
Once he had made one measurement. his curiosity was aroused and he began to investigate the general shape of the pond's basin. He made more than one hundred measurements of the pond's depth. From these he made a map, using his skills as a surveyor, and located the deepest point in the pond: "The greatest depth was exactly one hundred and two feet; to which may be added the five feet which it has risen since [with the spring runoff into the pond], making one hundred and seven" (237).
His curiosity further aroused, Thoreau began to consider generalizations arising from his quantitative measurements. "As I sounded through the ice I could determine the shape of the bottom with greater accuracy than is possible in surveying harbors which do not freeze over, " he wrote (288).
Measurements led to surprises. "I was surprised at its general regularity," he wrote. "In the deepest part there are several acres more level than almost any field which is exposed to the sun, wind and plough. In one instance, on a line arbitrarily chosen, the depth did not vary more than one foot in thirty rods; and generally, near the middle, I could calculate the variation for each one hundred feet in any direction beforehand within three or four inches. Some are accustomed to speak of deep and dangerous holes even in quiet sandy ponds like this, but the effect of water under these circumstances is to level all inequalities" (288-289).
Thoreau's investigation then went through a progression to ever more general theoretical constructs, leading to the development of a set of hypotheses about ponds and lakes in general. To do this, he had to find a means to aggregate his data so that Thoreau could see the result as a whole and think about that whole. For him, with his experience as a surveyor. this was the straightforward step of making a map. This required that his depth soundings be located geographically.
From the map he "observed a remarkable coincidence," he wrote, "the line of greatest length intersected the line of greatest breadth exactly at the point of greatest depth" (289). Now Thoreau had expanded his inquiry beyond the initial question of the depth of the pond. Having done a series of measurements, he began to see the pond differently, as if its bottom were a field, and he became curious about the shape of that field. Measurements had touched his imagination.
In reelecting on possible generalizations about his observations, Thoreau considered a comment made by somebody whose opinion he respected. "A factory owner hearing what depth I had found," he wrote, "thought that it could not be true, for, judging from his acquaintance with dams, sand would not lie at so steep an angle" (287). In this process Thoreau was not the mythical hermit avoiding human contact, but a person who considered the judgment of others when their experience and knowledge might seem valuable.
At this point he was beginning to move into an interesting thought process. A simple curiosity had led to a simple measurement, then to a series of those measurements, which had then led him to a consideration of whether the measurements could be correct and, if so, what they implied. Here, it implied that ponds could not simply always be shaped along the edges like dams of sand. "But the deepest ponds are not so deep in proportion to their area as most suppose," Thoreau continued, "and, if drained, would not leave very remarkable valleys. They are not like cups between the hills: for this one, which is so unusually deep for its area, appears in a vertical section through its centre not deeper than a shallow plate. Most ponds, emptied, would leave a meadow no more hollow than we frequently see" (287)
Based on his series of quantitative measurements, Thoreau began to speculate about the shape of ponds in general. He began to develop a hypothesis: perhaps the greatest depth of all ponds would tend to occur at the intersection of the line of greatest width and the line of greatest length. To test this idea, quantitative measurements were necessary. His scientific measurements piqued new curiosity, led to new kinds of questions, while leading to a new understanding. The new understanding brought him, in a different way than before, closer to nature.
Thoreau's study of the pond brings out another important distinction, that between observations and inferences, which are ideas that are developed based on a set of observations. A casual observation that Walden Pond looks deep is one thing, an inference from a single glance that it must be deep everywhere is another — it is a false inference. Confusing observations with inferences and accepting untested inferences is the kind of sloppy thinking often described by the phrase "thinking makes it so," and is something that continues to pose problems for dealing with nature and the environment.2
Applying Thoreau's Approach To Modern Environmental Issues
One would hope that this sound, fundamental scientific approach would be followed today. After all, it's been well known and well applied for several centuries. And one would hope it was applied to modem issues about nature – the very object to which Thoreau himself applied the method.
But sad to say, I have found over and over again that today's environmental issues often receive as much scientific analysis as the people who chose to sit by Walden Pond and guess at its depth.
Wherever possible, Thoreau tried to learn directly for himself. In general, he did not accept at face value what other people said. Perhaps the greatest example of this is his experience with his mentor, Emerson. As part of Transcendentalism, Emerson believed that nature was benign and cared about human beings. Thoreau listened to the great man and then went to the Maine woods where he climbed Mount Katahdin to see if this were true for nature at her rawest. He found that it was not true, at least not for himself.
When a subject came up that he could not answer in such a direct manner by himself, Thoreau sought experts, and he used expertise in a specific way. Once again, his approach is useful to us. Our society is confused about experts, especially scientific experts – about who is a scientific expert and about the role of scientists and science within our society. When Thoreau could not answer a question directly, he sought people who had had direct experience with the subject that concerned him. In his travels through the Maine woods, he was impressed by Joe Polis, his last guide there, and sought to understand how Polis could find his way so well in the forests.
But even with experts, Thoreau was cautious. He used the assertions of experts as hypotheses to be tested, as the beginning of exploration, not the end. This happened when he visited Cape Cod. There he learned that the Cape itself – its soils, it shape – was continually changing under the force of winds and water. He learned that first from the Wellfleet Oysterman and from other long-term residents of the Cape. One "told us that a log canoe known to have been buried many years before on the Bay side at East Harbor in Truro, where the Cape is extremely narrow, appeared at length on the Atlantic side, the Cape having rolled over it, and an old woman said – 'Now, you see, it is true what I told you, that the Cape is moving.'
Then he sought out the keeper of Highland Lighthouse, who he learned had lived there for many decades. The Highland Light was a landmark then as it is today, a classic white pillar rising above a white building on the edge of a picturesque dune, high above the beach and the water, facing to the east, to the open Atlantic ocean. It sits on the edge of an undulating landscape of dune grass, shrubs, small oaks and pitch pines, a mixture of patches of grasslands, shrub lands, and salt-spray-stunted, open woodlands. It is a lonely but picturesque landscape. The lighthouse stands on the edge of huge dunes that afford a grand view of the shore below. From the lighthouse, the dune falls away steeply for a long distance. Far below, at the base of the dune on which the lighthouse sits, people strolling along the strand appear as tiny toy figures.
The Lighthouse was built in 1798 to provide one of the major lights to guide ships away from dangerous shoals along the coast of the Cape, and it performed that function during Thoreau's time. Today, the lighthouse is automated and no longer has a keeper. The Lighthouse Keeper that Thoreau met agreed about the movement of the Cape. "According to the light-house keeper, the Cape is wasting here on both sides, though most on the eastern," Thoreau wrote (118). Thoreau listened, was intrigued by this hypothesis, and then constructed some surveying equipment from materials he borrowed from a carpenter, and made his own measurements. "I borrowed the plane and square, level and dividers, of a carpenter who was shingling a barn near by," Thoreau wrote, "and using one of those shingles made of a mast, contrived a rude sort of quadrant, with pins for sights and pivots, and got the angle of elevation of the Bank opposite the light-house, and with a couple of cod-lines the length of its slope, and so measured its height on the shingle" He observed that the dune rose 110 feet "above its immediate base" and 123 feet above mean low tide.
Next, he checked his measurements against those of other land surveyors. "Graham, who has carefully surveyed the extremity of the Cape, makes it one hundred and thirty feet," he wrote (118). Then he looked for signs of erosion — making qualitative observations. He found evidence of erosion about a half mile south of the lighthouse, at the point of highest land in the vicinity. There along the dune he saw streams "trickling down it at intervals of two or three rods" which left erosional shapes like "steep Gothic roofs fifty feet high or more," which were at one location "curiously eaten out in the form of a large semicircular crater" (118).
Still not content with the opinion of the lighthouse keeper nor the measurements he was able to take himself, he examined data kept by the lighthouse keeper. "We calculated, from his data, how soon the Cape would be quite worn away," Thoreau wrote (118-119, emphasis Thoreau's). Thoreau made additional measurements when he returned to the Cape the following summer. "Between this October and June of the next year I found that the bank had lost about forty feet in one place, opposite the light-house," he wrote (119). From these observations he concluded that the Cape was wearing away about six feet a year. But he was cautious about simple extrapolation and generalization from a few observations. "Any conclusion drawn from the observations of a few years or one generation only are likely to prove false," he wrote, "and the Cape may balk expectation by its durability." This skepticism — even about one's own measurements and observations is one of the important features of science and of scientists.
The steps are clear: first, learn for yourself if at all possible; second, if not, select your experts carefully – make sure they have had direct experience; third, listen to what they say and treat that as a hypothesis; fourth, test the hypothesis for yourself.
This is the path to knowledge we followed with Jim Welter. We viewed his graphs of salmon and water flow, and then made extensive statistical analyses to see if what looked to be the case held up under analysis. It did.
This way of selecting experts and using their knowledge was useful in our situation and can he useful today. It is not the role of scientists, as experts, to make policy, but to advise us about what is possible based on their knowledge and about how we can achieve the choices of the possible, what we gain and what we give up. Then in a democratic society it is up to us to decide which of the possible choices we wish to pursue.
Encompassing all these specific ways that Thoreau's life and writings can be of direct use to us in solving our environmental problems is his love of nature and his life-long search for ways to combine both a physical scientific and a spiritual contact with nature. These, and his love of learning and of civilization, are guides to us for today and the future as we struggle to find how we can conserve our surroundings and maintain the best that human civilization can offer.
1 Thoreau, Henry David. Walden. J. Lyndon Shanley. ed.. Princeton, N.J.: Princeton University Press, 1971, 285.
2 In this discussion of the scientific method I am indebted to Dorothy Rosenthal, who wrote chapter 2 in Botkin, D. B. and E. A. Keller, Environmental Science: The Earth as a Living Planet . Third Edition. New York: John Wiley and Sons, 1999.
3 Thoreau, Henry David. Cape Cod. Joseph J. Moldenhauer, ed. Princeton, N.J.: Princeton University Press, 1988, 120-121.
4 The original talk was published as Botkin, D. B., 2001, “The Depth of Walden Pond: Thoreau as a Guide to Solving Twenty-first Century Environmental Problems,” The Concord Saunterer N. S. 9: 5-14.