Epilogue - Reef Madness: Charles Darwin, Alexander Agassiz, and the Meaning of Coral - David Dobbs

Reef Madness: Charles Darwin, Alexander Agassiz, and the Meaning of Coral - David Dobbs (2005)

Epilogue

THAT ALEXANDER AGASSIZ did not publish his coral reef theory-that this most effectual of scientists and administrators, a man who completed countless projects started by both his father and himself, accustomed and even compelled to finish things, should fail to complete the most consuming work of his life-constitutes an irony of the sort usually reserved for scripted tragedy It’s only one among a long list of ironies painful to contemplate: that Alex, taking up a question seemingly made for him, should find him self locked in endless struggle with the man who destroyed his father. That every lesson Alex learned watching his father’s destruction-his aversion to idealist thought and deductive method; his devotion to induction; his resistance to early conclusions or simple answers; his distaste for debate-should hamper him in his own battle with Dar win. That his conflict with Darwin should form a near mirror image of his father’s, only this time with Darwin holding the lovely story and Alex the deep box of empirical ammunition, but Darwin winning anyway. That he should overlook the implications that his father’s ice age theory held for reef formation, and that those implications should be seen and published by another even as he died.

Alexander Agassiz suffered these ironies partly because he was stubborn and partly because he was profoundly luckless. But these ironies also illustrate just how difficult a spot he stood in. He occupied a uniquely conflictual position during a time of immense contradiction and change. Both as a scientist and as a man, he was caught between the two figures who most excitingly personified the philosophical and methodological views that science was struggling to reconcile during the nineteenth century. Their conflict illuminated the starkness of the choice facing science and intellectual culture even as it hid the tangle of contradictions complicating that choice.

Alexander Agassiz, in his mid-sixties, circa 1900

But if Alexander was more ensnared in these tangles than most, he was hardly alone. As science moved from the Victorian age to the modern, its great changes in method and philosophy and its immense gaps between orthodoxy and practice caused any number of scientists to be hoisted by their own petards. The comeuppances abound: Darwin, obsessed with oscillating landscapes, climbs too high at Glen Roy and falls when undercut by Louis’s glacier theory.

Louis, thus emboldened, disastrously overextends both his glaciation and his speciation theory-and gets upended twenty years later by a Darwin wielding the empiricist principles Louis preached. Lyell, infecting Darwin with his vision of generative change, cheers as Dar win overturns his own coral reef theory and then flinches when his protégé proposes a blasphemous theory of selection. The devout Asa Gray, led by Darwin up his own careful stairway of evidence, arrives at the top to see a world purged of God. There was comedy as well: Lyell wishing Louis’s lovely story were only true; Huxley turning Wilberforce’s ape insult back on him; Huxley smeared with his own Bathybius. Hardly a notion or an action doesn’t somewhere circle back to blindside its maker. It’s as if every act and idea entered a warp and turned back on itself

The distorting force, of course, was science’s attempt to leave behind the idealist master it had so long served. This attempt had led to the Baconian method two centuries before and in Darwin’s time to the argument between the Whewellians, who would have scientists collect evidence to build a theory, and the Herschel followers, who felt it acceptable to hatch a theory early and then buttress it with evidence. The Baconians and Whewellians stubbornly resisted the “danger of leaps” that Herschel’s method seemed to invite. You had to climb the steps one at a time, and they all had to be visible. Thus Gray attacked Louis’s creationism. Thus Alex, Murray, Geikie, and others balked at the speculative nature of Darwin’s coral theory, which seemed a “simple and beautiful” idea until it faced the evidence.

The problem with so strict an inductivism, the reason it caught so many people in such agonizing binds, is that it ignores the way our minds operate. We see or experience a phenomenon, jump to conclusions about it, then (if we aspire to rigor) check our conclusions against more evidence. An idea rises not as the inevitable product of accumulated fact but as an early abstraction of experience. Its accuracy and utility reside not in its genesis but in how it tests out. This is the irony that underlies all the others: In their determination to create a method that could reflect only how nature actually works rather than how we think it should work, the inductivists prescribed a method that substituted the way they thought the mind should work for the way it actually does work. They pushed an idealist conception of nonidealist theory generation. It tied them in knots. Whewell, soaked in the history of great ideas, turned himself inside out trying to explain, via his concept of “colligation,” how a series of observed facts accreted into an idea. He couldn’t do it, because facts don’t mount to an idea. They require an act of imagination-or recognition, if you’d rather-to fuse them into an explanation.

Herschel’s model worked better. It relieved the scientist of proving that a theory rose from evidence and demanded only that evidence support it. It was okay to raise the shell and then fill in the frame. It wasn’t really inductive, but it was still empiricism, tied to observation and testable experiment, and it allowed more powerful theorizing.

This Herschellian model gave greater recognition to the role of imagination, speculation, and the perception of broad patterns of distribution and change. It was a move toward the power of story. Explanations of complex dynamics naturally lean to narrative because they have to explain not what is, as taxonomy does, but how something happens. Thus the fates of the speciation theories of Louis Agassiz and Charles Darwin. Louis’s foundered because he overlaid an idealist story onto a science he claimed was descriptive; he lost his credibility when his fight with Darwin, who told a story driven by natural processes, made it obvious that Louis told a story driven by divine action.

Along with the elimination of divine cause, it was the acceptance and emphasis of story-the focus on dynamic natural processes of change rather than fixed descriptions of static things-that distinguished the shift in science that occurred during Darwin’s and Alex’s time. It was only the purging of divine cause, of course, that made storytelling safe. Even so, it took science another lifetime after Louis’s and Darwin’s era to admit that it used stories (and many scientists today would deny it yet). But the practical acceptance of empirical story rather than description as science’s main job began with the acceptance of Darwin’s ideas, and his first such story was not his evolutionary theory but his coral reef theory. Alex accepted the evolutionary theory because it was built on two decades of accumulated fact and observation. It didn’t come across as a story. He rejected the coral reef theory because Darwin had published it on so little evidence and it was built on a foundation-and a flimsy one at that- that seemed jerry-rigged after the fact. Alex had seen stories like that before.

THE ROLES of imagination, story, and even metaphor would expand further in the decades after Alex died. In particular the rise of physics, with its abstractions and elusive, hard-to-observe phenomena-subatomic particles, invisible forces such as gravity and energy, space-time and quanta-forced a revision not just of the rules of theory but of what a theory was. The concept of a theory as a definitive account of something-the sort of one “true theory” that Dana and Jukes saw in Darwin’s coral reef hypothesis, for instance- yielded to the notion of a theory as a phenomenon’s provisional approximation, and not necessarily the only approximation. Gravity was not just the force Newton described; it was also a curve in space-time. Light was at once wave and particle. This conception of theory acknowledged that we often see evidence partially or indirectly. It also acknowledged that, as Heisenberg’s uncertainty principle suggested, observing a phenomenon can warp it. Heisenberg was refer ring to the way the process of locating a subatomic particle, which required bouncing a photon off it, could unpredictably alter the particle’s location and path. But his principle expressed the growing awareness that observation sometimes failed and that even the most basic laws we perceive in the universe, such as those of gravity, are not complete accounts of a dynamic but our best working description of it. The notion of a theory, in short, changed much as the notion of species had, from something fixed to something provisional and capable of change, even expected to change.

This revised theoretical model was articulated eloquently in the 1920s and 1930s-by which time it carried the term “hypotheticodeductive theory”-by a German-born philosopher named Karl Popper. A sort of twentieth-century Herschel, Popper explored brilliantly how individuals wielded this method and how science or society tested the resulting theories (or failed to). Popper argued that we should not only be willing to accept a theory created deductively but that we should expect a theory to be created deductively, for that is how ideas come. He also argued that we should consider a theory scientific not simply because it is backed by evidence-for you can find evidence to back almost anything-but only if some observation or experiment could conceivably prove the theory false. He called this the “principle of falsifiability” Newton’s theory of gravity for instance, was a valid theory because it could potentially be proven false by a body that would not fall, and his laws of motion were valid because they could be falsified if some action produced no commensurate reaction. Accordingly, such theories as Freudianism or Marx ism weren’t scientific (though they might be useful) because you couldn’t imagine any phenomena within their purviews that they couldn’t explain. The great strength of psychoanalysis as an instrument of understanding-its ability to explain any human act or emotion-becomes its negation as a science.

A theory that could explain truly anything, then-that is, to which no conceivable exception could be imagined-was not scientific. A theory to which possible falsifications could be conceived and then attempted was scientific, for only attempted but failed falsifications could prove the theory’s truth. Science thus progressed by a constant testing of theories for weaknesses (Popper called these tests “attempted falsifications”) and the revision or replacement of the theory as necessary. Challenge, negation, and succession was science’s proper course.

This model gives science an admirable rigor. But for scientists it envisions an antagonistic, almost gladiatorial world in which to work.

It was the bad luck of Alex, who abhorred open conflict, that one of the first ambitious and rigorous applications of the hypothetico-deductive method was Darwin’s coral reef theory. Alex found himself chief challenger in an attempted falsification that lasted a century. He didn’t see it that way, of course; he simply wanted to refute the results of a method he thought corrupt. He objected both on evidentiary grounds-because he saw so many things that seemed to disprove Darwin’s theory-and because the theory was deductive on its face. Darwin was operating under the rules of an age still to come. Alex was applying those of his own era. At a time when scientists had good reason to forbid speculation from outrunning observable evidence, Alex, whose father had tripped himself up by doing just that, chose to take on a theory that by every rule of science he knew should be discarded. As Alex pointed out, Darwin’s argument was ultimately circular, for he tried to explain reefs by a cause-subsidence-of which the reefs themselves were the main indication. The cause was to be its own proof. Accordingly the theory rested not on direct evidence of subsidence but on reef forms and their distribution. William Davis had been right: The maps really were Darwin’s best evidence. But Davis was the only one to admit this. Other subsidence advocates of Alex’s time, citing the power of Darwin’s argument and its “complete correspondence with observation” (Dana), fooled themselves when they called the theory good science, because by their own formal rules of science it wasn’t. Even by Popper’s rules it was more an interesting theory rather than one validated, for the only conclusive test was inaccessible: You could not imagine a reef or map that would contradict Darwin’s theory. Until Eniwetok, definitive evidence lay in an untestable dimension.

As it happened, Eniwetok proved Darwin right. In the meantime Darwin’s theoretical approach, boosted by his own evolutionary the ory, the spectacular deductions of Einstein, and the explications of philosophers, was accepted, elaborated, codified, and given a long, ugly name. But in Darwin’s and Alex’s day, the hypothetico-deductive method was called speculation, and it was a dirty word. Alex’s biggest mistake was truly unforeseeable: In coral reefs he addressed a problem that in his time remained unsolvable. He tested it as thoroughly as he could. But it was given to another age to find the answer.