The MacArthur Foundation's 'genius' awards embody the classic Campbellian myth: the way to make great, positive changes in the world is to locate individual heroes, give them a million dollars, and let them be creative. In contrast, the Nobel Prizes are frequently awarded to more than one person; these awards seem based on the idea that discovery can be a collective effort.
For example, Watson and Crick shared the Nobel prize for the discovery of the double helix structure of DNA. But as even Watson's entertaining, irreverent account of their discovery showed, they relied heavily on the work of others who were close on their tails (Watson, 1968) and there were other good candidates for inclusion in the award (Portugal & Cohen, 1977).
Similarly, Banting and MacLeod were both awarded the Nobel Prize for the discovery of insulin--and each promptly selected another colleague to share the award. Furthermore, the major paper announcing the discovery actually had seven authors (Bliss, 1982).
The negotiations among scientists about who deserves credit are frequently acrimonious; each of the original recipients of the insulin award thought the other did not deserve it, and the battle continued long afterwards. To find out more about the nature of the negotiations that lead to and follow up on a discovery, we once again need a case that has been studied in sufficient detail.
This controversy concerns the discovery of what we now call the Devonian period in geological history. The name comes from Devon, in England, where the strata that came to typify the Devonian sequence were first identified. This discovery grew out of an often acrimonious set of negotiations among at least ten major participants (Rudwick, 1985). In the interests of simplification, we will stick to a few main characters and a sub-set of the full story.
Roderick Murchison was a gentleman who had taken up geology because it afforded him a respectable hobby that could be combined with the pleasure he took in hunting. His mentor was another gentleman geologist, Adam Sedgwick, a respected president of the prestigious Geological Society. Murchison succeeded him in that post.
One of the controversies in the geology of the 1830s concerned the relative importance of two methods for dating strata: fossils and rock types. Murchison, who did his fieldwork in the Yorkshire, became impressed with the heuristic value of using fossils to date strata.
In contrast, Henry De la Beche, secretary of the Geological Society under Murchison in 1831, tended to favor rocks over fossils. As of 1831, younger and more recent strata were relatively well understood, but below the Carboniferous group was a large, undifferentiated area known as the Greywacke, the upper part of which was an area of "Transition limestone". Between the two was an area known as the "Old Red Sandstone".
In 1831 Murchison had an Eureka insight when he found a place where the Transition passed conformably into the Old Red. Actually, the Eureka was a myth; Murchison and at least one other geologist had observed this phenomenon before. Successful discoverers are also good at myth-making.
By 1834, Murchison had developed a hypothesis: that the Old Red Sandstone was divided into three parts, the middle of which had fish, but no plants; below that, the Transition also had sea fossils, but most of the Greywacke below had none. This hypothesis had economic implications in the search for coal, which--if Murchison were right--had to exist above the Old Red.
What appeared obvious in one area of England might look entirely different in another. When De la Beche did a survey in Devonshire in 1834, he found evidence to accord with his presuppositions--that fossil plants existed throughout the Greywacke, and therefore coal could be found in Greywacke as well.
Murchison and De la Beche had been sparring in letters already, but now the controversy broke into the open at a meeting of the Geological Society in December of 1834. Essentially, Murchison focused on fossils--if De la Beche had found Carboniferous fossils, then he had Carboniferous strata. De la Beche, who had actually studied the rocks, felt they looked like Greywacke. Indeed, he wrote a letter to another geologist in which he depicted himself confronting Murchison and his colleagues and, pointing to his nose, announcing, "This, Gentlemen, is my Nose," to which they responded:
My dear fellow--your account of yourself generally may be very well, but as we have classed you, before we saw you, among men without noses, you cannot possibly have a nose (Rudwick, 1985, p. 104).
De la Beche initially won Sedgwick's support, in part on the grounds that Murchison had found no distinctive Greywacke fossils and therefore his case hung on the absence of fossils, rather than on the presence of a distinct variety. Murchison then back-tracked a bit, claiming there were distinct fossil plants in the Old Red, although they were too poorly preserved for clear identification.
In 1835, Murchison, working in his Welsh Borderland area, labeled his Transition strata Silurian and confirmed that they contained no plant fossils. He also found a place where De la Beche had mistakenly applied the label Greywacke to Carboniferous coal-bearing strata. This piece of evidence was crucial in converting De la Beche's chief backer, Sedgwick, into a supporter of Murchison's view. While Murchison was discovering the Silurian system, Sedgwick was discovering the even older Cambrian system. Murchison referred to these groups of strata as systems because he was convinced that they were general and could be found anywhere in the world where erosion, eruption or other local disruptions had not erased them.
In July of 1836, Murchison and Sedgwick 'invaded' De la Beche's home ground, North Devon. They had hoped to find evidence of a discontinuity from the Carboniferous coal-bearing strata to the older Greywacke, caused by the way the strata were folded and had eroded. Instead, they found support for De la Beche's claim that there was a gradual transition. Despite the puzzling lack of an obvious discontinuity, they hypothesized a great trough of Carboniferous coal measures in the center of North Devon, which made an abrupt, unconformable transition to Silurian on the north side and Cambrian on the south.
In August of 1836, they presented their findings at a meeting of the British Association in Bristol. By the time of the meeting, Murchison had added a fourth band, or system, of strata, which he labeled 'Devonian'; on his map, these Devonian strata appeared between the Silurian and Cambrian systems north of the great Carboniferous trough in Devon. Sedgwick re-labeled these strata 'Upper Cambrian'. At this point, Murchison and Sedgwick obviously felt there was something different about this transition from Silurian to Cambrian, but they weren't sure what. Figure 4 compares De la Beche's hypothesis to Sedgwick and Murchison's.
Figure 4: Competing hypotheses about the structure of the same geological strata. A corresponds to De la Beche's view, B to Sedgwick and Murchison's. Reprinted with the permission of the University of Chicago Press from (Rudwick, Fig. 7.6, p. 164).
De la Beche was given an opportunity to respond at the meeting. "I was taken most deucedly in the flank, my ammunition being in my magazines, and my guns dismantled, expecting nothing but peace, I made my retreat in the best manner I could" (Rudwick, 1985, p. 166). He conceded the plausibility of the Murchison-Sedgwick re-interpretation of the north Devon strata, but argued that there was nowhere any evidence of the unconformity that should have been observed. Later, he objected to this 'slapdash' introduction of new systems into Devon by geologists who had not studied the rock as carefully as he had. He was the one professional geologist in this group, hired to do the survey--his job was on the line, as well as his reputation.
Then a local geologist in Devon discovered plant fossils in strata Murchison and Sedgwick had labeled Lower Silurian. Murchison had claimed there would be no plant fossils this far down. He resolved this apparent anomaly by re-classifying these Silurian strata as Old Red Sandstone. Sedgwick laughed-off this interpretation and chided Murchison for relying too heavily on fossils. Though both authors agreed that De la Beche's hypothesis was wrong--and by this time, even De la Beche agreed it needed modification--they could no longer agree on all the details of their own hypothesis. The sticky problem of the missing unconformity remained unresolved.
Fossils from the strata in contention showed strong parallels with the Carboniferous but with some additional, new fossils, none of which were from the Silurian. Nor did these fossils seem characteristic of the few that had been found in the Old Red. These fossils were found by Austen, one of the large group of talented amateur geologists who entered the controversy, and were identified by fossil specialists in London. In other words, a broadening network of actors was playing a role in this controversy, which was featured prominently in William Whewell's Presidential address to the Geological Society in February of 1838.
That summer, Sedgwick read a paper which focused primarily on his Cambrian system, which had few fossils, therefore making a correlation across regions particularly difficult. Sedgwick conceded that there was no unconformity in North Devon, which meant post-Cambrian and post-Silurian strata had to go down much farther than either he or Murchison had proposed previously. Sedgwick still claimed that the bulk of the strata of Devon were upper Cambrian, but only in one location in Cornwall was he absolutely sure, and from that location he derived a few fossils characteristic of the Cambrian. In a subsequent field trip, he found these characteristic fossils in other places he had identified as Cambrian, but also ones characteristic of later periods.
Shortly afterwards, Murchison published his magnum opus on the Silurian System; towards the end, he speculated that the Old Red Sandstone might be a system like the Silurian, which could be found all over the globe. As yet there were no characteristic fossils. No coincidence, De la Beche published the report of his survey shortly afterwards, and criticized the idea that local arrangements of geological strata represented systems valid globally. Furthermore, fossils were as local as strata, in the sense that a species that flourished at one time in England might flourish under the same conditions centuries or even epochs later in another part of the world. For De la Beche, the fact that species characteristic of the Carboniferous appeared in rocks he labeled Greywacke did not mean these were more recent strata; it simply meant that these species had flourished at different times in different places.
Murchison had paved the way for a solution to the Devonian problem with his suggestion that the Old Red might be a system. Perhaps the questionable strata in Devonshire belonged to the Old Red. However, this new hypothesis meant making three major concessions to De la Beche:
1) There was no unconformity below the Carboniferous in Devon; instead, Carboniferous passed conformably into Old Red.
2) The fossils in the proposed Old Red in Devon were not identical to those found in the Old Red elsewhere, which meant that Murchison would have to agree that fossil evidence was not totally reliable, that there were important local variations which could make using the fossil record problematic.
3) De la Beche had even hinted that there might be Old Red sandstone in Devon, although his overall interpretation of their place and role differed from Murchison's.
Finally, there was another problem. Sedgwick objected to this Old Red idea because it corresponded to strata he had labeled Cambrian--the amount of Cambrian in England was shrinking, and with it the possibility of finding more than a handful of distinctive fossils so it could be extended world-wide, like the Silurian.
Murchison persuaded Sedgwick to adopt this new hypothesis and the two published a paper written by Murchison in the Philosophical Magazine. Instead of conceding his debt to De la Beche, Murchison attacked him for using parts of their re-analysis of Devon without giving him credit--and then appropriated some of De la Beche's views as if they had been his own! Specifically, Murchison pointed-out that he and Sedgwick had discovered the coal- measures trough in central Devon, but also claimed they noticed how it passed conformably into strata below, giving De la Beche no credit for this discovery.
Then Murchison made a classic rhetorical move. He gave the widely-recognized fossil specialist William Lonsdale credit for realizing that "the South Devon rocks would be found to occupy an intermediate place between the carboniferous and Silurian systems" (Rudwick, 1985, p. 283). Indeed, Murchison chastised himself for not reaching the obvious solution sooner, and claimed he had relied too heavily on the character of the rocks and not enough on the fossils! This was a total rewrite of the actual history of the controversy to make it appear that the solution had been obvious all along and that it was really proposed by an authority outside of the controversy. The end of the article proposed a new Devonian system equivalent to the Old Red Sandstone that lay between Carboniferous and Silurian. Murchison conveniently glossed over many of the remaining difficulties, including the fact that there were no clear Silurian strata under the new Devonian system in Devon, nor did the new system have any truly characteristic fossils. The article was a brilliant polemic.
Murchison canvassed members of the Geological Society shortly afterwards, and happily concluded that if De la Beche attempted an angry rejoinder, "we have enough powder and shot in our tumbrils to sink him" (Rudwick, 1985, p. 287). Murchison eventually apologized for some of his more pointed remarks, but made no concessions regarding the new system, which he now traced to an even more respected elder, the fossil specialist William Smith. Murchison had now placed himself firmly 'on the shoulders of giants', to adopt Newton's felicitous phrase. He conveniently ignored the contributions of lesser, Devon geologists like Robert Austen who provided much of the fossil evidence.
The leading participants began to reach a consensus on this new point of view--even De la Beche conceded that the Devonian hypothesis had merit, especially as he felt the new synthesis vindicated some of his earlier views. But consensus was by no means universal, and could only be achieved by looking for the Devonian elsewhere. Murchison and Sedgwick traveled to the continent, where they were assisted by able European colleagues. "In the course of their long expedition, Murchison had turned most of the ancient Greywacke of the Rhineland into Devonian, only to find himself forced by the fossil evidence to turn much of it back into Silurian, leaving his confidence in the Devonian precarious if not collapsed. Sedgwick has seen his potential Cambrian annexed by the Devonian but later at least partially restored. He had totally lost confidence in the Devonian interpretation, of which he had been the nominal co-author only six months earlier. But whatever their differences, it would have been clear to both geologists that their best hope of resolving the Devonian problem, after almost five years of controversy, lay packed inside the boxes they had been sending back to London" (Rudwick, 1985, p. 329).
The newly discovered Devonian system was now on its deathbed--Sedgwick renounced it, Murchison had doubts, and others would soon follow. But Lonsdale and the other fossil experts showed that there was indeed a unique, intermediate group of fossils--that some of what Murchison and Sedgwick thought was Silurian was in fact Devonian. The difficulty was that there were Silurian fossils in the Devonian strata, in addition to other new fossils that promised to be characteristic of this system. Even with this evidence, Murchison had to work hard to persuade others. He took the campaign to Russia, where he found further evidence of the three systems and found evidence for a fourth, the Permian system.
Who discovered the Devonian? Clearly Murchison became its champion, the one who really persuaded others that it was a system--indeed, the one most responsible for the widespread adoption of the idea of a geological system. But if one asks who first found the evidence that pointed towards a new set of strata in Devon, then the picture becomes more complex: Lonsdale, Austen, Sedgwick and even De la Beche can be said to share part of the glory. In particular, after Lonsdale's fossil analysis resurrected the Devonian, geologists moved quickly to give him credit for discovering the system. Murchison and Sedgwick had to mount a counterattack to salvage their own claims, showing that not just fossils but field evidence played an essential role in establishing the Devonian.
The point is, the Devonian emerged out of a complex set of negotiations involving a number of actors. In contrast, the Silurian was more clearly a Murchison discovery and the Cambrian more clearly attributable to Sedgwick.
The three discoveries discussed so far have been modeled or simulated on a computer. No one has done this with the Devonian case, but Paul Thagard (Thagard, 1988) has simulated the resolution of a number of other controversies, including the oxygen/phlogiston debate and the controversy over whether a comet caused the extinction of the dinosaurs (Thagard, 1990). He used a connectionist algorithm in which a theoretical position is represented as a network of connections among hypotheses and pieces of evidence. A connectionist model of Murchison's Devonian hypothesis, as he presented it in the Philosophical Magazine, might include positive connections to the hypothesis that there were global geological systems, to evidence to the conformable passages in the Devon strata and to some of the fossils, but negative links to other fossil evidence and to the fact that there were no Silurian fossils. De la Beche's Greywacke alternative would have positive links to the conformable strata, but negative links to fossils and to the idea of global systems. If we ran a Thagard-type program, Murchison's hypothesis would doubtless win.
But note that we set up the links in this connectionist simulation from Murchison's perspective. If we took De la Beche as the primary viewpoint, any links to a universal system would be negative because he was suspicious of this idea, and links to fossil evidence would be at best neutral. As Thagard admits, one can set up a connectionist simulation so any side in a controversy wins, depending on whose perspective one takes.
The real value of Thagard's simulation is that it could allow one to experiment with what evidence might change a participant's point of view, if they were evaluating the evidence rationally. For example, what would a simulation built from Murchison's perspective do if one added a negative link between the Devonian hypothesis and the first geological evidence from the Continent, which suggested there were no Devonian strata? Would this be enough to cause the weights for the Devonian hypothesis to fall below a critical threshold? Could one also add in a negative weight for the defection of his main collaborator, Sedgwick, and see how that affected the result? All the weighting would be somewhat arbitrary, of course, but the point would be to play with the various connections and combinations, as a means of getting new hypotheses about the resolution of the controversy. Unfortunately, instead of seeing his connectionist simulation as a tool for play and exploration like Gooding and Addis' expert system, Thagard has argued that his simulation proves the correctness of his own philosophical position regarding the resolution of controversies (Gorman, 1989(a)). The point is, you could create a simulation from another perspective and show that worked as well--but it would work differently, and that is where the fun begins.
There is still no multi-agent simulation that will allow us to create different agents with different agendas, run the simulation, and gain a new perspective on how the different actors in the controversy might have interacted under different circumstances.
Is Murchison the hero in this controversy? If so, he is a different kind of hero than the 'disinterested pursuer of truth' that has been our guiding heroic metaphor to date. Murchison is more like a general, with his frequent references to campaigns and artillery. His goal is to defeat De la Beche and then conquer the world with his and Sedgwick's geological systems. De la Beche also uses military analogies to describe his reversals in the battles.
Contrast this competitive picture of the motives for doing science with the following, "If someone, for example, Charles Darwin, becomes fascinated by science, the work itself draws him on; if he works hard it is because the task is hard and he is engrossed in it... If he seems ascetic, it is because no jewel is more beautiful than the atom, no luxury cruise more fascinating than a voyage of discovery. The simple idea of task involvement provides the basis of understanding the organization of purpose of the working scientist" (Gruber, 1989, p. 250).
The exciting and frustrating thing about human beings is that, unlike billiard balls, we have multiple motives. It is no contradiction to seek a scientific truth in order to flatten an opponent. Indeed, this sort of competition may be critical to the advancement of science. Murchison alone could not have discovered the Devonian system. He needed to recruit allies, fight opponents and in the course of this, alter his own views to accommodate those of others, all the while denying any significant change in his position.
Could a multi-agent computational simulation have achieved the same result without these 'hot' motives? In the next chapter, we will consider a simulation with human beings that might help answer this.
Let us see how the Devonian case affects our generalizations about discovery.
1. Discovery depends on finding a problem significant enough to be labeled an important achievement.
The problem of the geology of Devon was certainly of local significance. Murchison deserves some credit for turning it into a problem of global significance by claiming that systems should be universal. A discoverer can play an important role in establishing the significance of a problem. Therefore, this generalization should be modified:
1. Discovery depends on establishing that a problem is significant enough to be labeled an important achievement.
If there is already a consensus that a problem is important, then a scientist needs to establish that her/his work is relevant to the problem.
Sometimes others establish this relevance post-hoc and even post-mortem. Consider the case of Gregor Mendel. According to the heroic myth, his 1865 paper on cross-breeding of traits in peas across successive generations was so revolutionary no one understood it at the time. In fact, it was well-received because, as Sir Ronald Fisher pointed out,
Each generation found in Mendel's paper only what it expected to find: in the first period, a repetition of the hybridization results commonly reported, in the second, a discovery in inheritance supposedly difficult to reconcile with continuous evolution. Each generation, therefore, ignored what did not conform to its own expectations (Brannigan, 1981, p. 102).
Indeed, others in the mid 1800s had found results similar to Mendel's. In fact, Fisher argued that Mendel's ratios were too perfect, suggesting that he knew what results he ought to get, and that influenced his classification of the peas. The mantle of discoverer was awarded to Mendel by a later generation; Gregory Bateson and others established him as champion of the view that inheritance depended on combinations of dominant and recessive genes. Mendel certainly raises these issues in his paper, but it is not clear that even he saw their full significance for the evolutionary debates raging at the time (Brannigan, 1981).
The first of the 're-discoverers' made a move similar to Murchison, who attributed the discovery of the Devonian to Lonsdale. Similarly, Hugo DeVries cited Mendel in a 1900 paper as an after-thought because DeVries immediately became involved in a priority dispute concerning the discovery of the laws of segregation and dominance. Correns, one of DeVries' competitors, realized he was going to lose the priority dispute and so neutralized that loss by speculating that DeVries owed his discovery to a close reading of Mendel's paper (Brannigan, 1981). Similarly, one might label Lonsdale the discoverer of the Devonian system only because Murchison established the significance of his fossil work and used his name to neutralize opponents.
2. Discovery depends on transforming that problem into a form that suggests a promising path to solution.
Murchison and others had to agree on the nature of the problem in North Devon before it could be solved. Was there really a problem at all? If so, what should be the role of fossils and rock types? Was one looking for a universal system or a local one? Whose expertise should weigh heaviest in debates? Problem creation and transformation often depend on intense negotiations among scientists. Again, the Mendel example is relevant--the significance of his work was transformed by other, later scientists.
3. Discovery depends on finding or inventing good data.
The Devonian case illustrates that what constitutes data is often the outcome of a process of negotiation. De la Beche's analysis of the rocks in Devon--as obvious to him as his nose--was dismissed by Murchison because he regarded the evidence from fossils as more important. But when it appeared everyone would take Murchison's rhetorical move seriously and label Lonsdale the discoverer, Murchison had to appeal to rocks to restore his own claim.
BACON was given the data that was produced by the long set of negotiations between Kepler, Brahe and others. Similarly, one could give a program--perhaps Thagard's--the picture of the data that emerged as a result of the controversy, and show that the program would reach the same conclusion as the participants. But the conclusion, at this point, would be embedded in the data.
Here generalizations two and three begin to merge. Transforming the problem transforms the data; transforming the data transforms the problem. So we could synthesize these two generalizations:
2. Discovery depends on transforming that problem into a form that suggests a promising path to solution, which includes locating and transforming the necessary data.
This is a much more controversial generalization than the previous one, as we will see in the next chapter, when we consider the cognitive literature on scientific problem-solving.
4. Discovery depends on a combination of flexibility and stubbornness, depending both on the individual scientist's cognitive style and on the nature of the problem.
The Devonian controversy shows how patterns of flexibility and stubbornness occur partly as a function of negotiations among participants in a controversy. Murchison appeared the most stubborn partly because when he changed his mind, he disguised the fact, as much as he could, to establish that his view was, and always had been superior to his rival De la Beche's. In contrast, De la Beche, who publicly made much greater concessions than Murchison, stuck to his view that there was a continuous series of conformable strata in Devon and in private, ridiculed Murchison. Sedgwick was perhaps the most flexible, beginning as an ally of De la Beche's, then shifting strongly to Murchison, gradually and reluctantly allowing the Devonian to supplant his Cambrian system in Devon.
One could argue that Sedgwick was the most secure of the three, in terms of his reputation, social position and employment. Murchison was out to make a name and carve out a new career, but had independent income. De la Beche's primary source of income was the survey, so he had to proceed in a way that antagonized as few geologists as possible.
So, this generalization places too much emphasis on the individual. We might re-word it as follows:
4. Discovery depends on a combination of flexibility and stubbornness, depending on the cognitive styles and career trajectories of the scientists involved and on how they represent the problem..
We could list a great many more factors in this generalization, but these few words will give the flavor. Whereas Faraday had to work hard to maintain the right balance between mental inertia and flexibility, it is possible in a controversy for some participants to adopt a more stubborn cognitive style, with flexibility emerging grudgingly out of competition. 'Career trajectories' can include relative eminence in the field, strategies for improving one's position and current or expected sources of funding. Problem representation can include theoretical commitments, like Sedgwick's desire to see his own Cambrian writ large--therefore, part of his problem in Devon became finding Cambrian fossils, which colored his perception of the strata.
5. The act of writing is part of the discovery process.
The act of writing in the Devonian controversy is an intimate part of the negotiations. Indeed, were it not for letters, there would be no detailed study of this controversy! Therefore, this controversy adds a type of writing to our list, which now includes letters--or e-mail in modern times--alongside notebooks and drafts of articles.
The four surviving generalizations suggest that discovery is not entirely mysterious, and that it can be taught, or at least encouraged. We hope to make them more precise by going more deeply into the relevant psychological and sociological literature in the next chapter.
This page was last edited: Wednesday, July 14, 1999