SETI: A Critical History: Conclusion
Once Cocconi and Morrison suggested the possibility of communicating with ETIs by radio, SETI's architects were eager to get to their radio telescopes and begin searching. They almost casually adopted the Drake Equation as "the definition of all the problems" related to a SETI-style search and fashioned a rationale for their project whose criterion – plausibility – admitted bold assumptions. The SETI scientists claimed to be establishing the ETI discourse on a rigorously scientific basis for the first time and believed that their project would secure a prestigious institutional home in NASA, where the search for extraterrestrial intelligence would be part of the space agency's broader mission to search for extraterrestrial life. Like radio astronomers, the American public was immediately drawn both to SETI and to the super-humanoid "SETI-ETIs" that SETI targeted. A Cold War-weary society found in them a hopeful allegory for how to address terrestrial fears, and together they left a heavy imprint on films, television, and popular science texts (see science fiction involving extraterrestrials, after 1940).
For the next fifteen years, however, NASA was too busy meeting existing commitments to turn its full attention to SETI. During that long interval the ETI discourse began to undergo a profound transformation. For millennia, contributors to the broader ETI discourse ignored the question of what ETIs' cognitive structures, consciousnesses, and intelligences might be like; they assumed ETI's nature would be similar to their own. This assumption carried an important corollary: humans would find it relatively easy to communicate with ETIs. SETI's architects conceived their project within this traditional ETI discourse and assumed humanoid ETIs. As the ETI discourse expanded it was no longer constructed simply around the question of whether ETIs exist; it began to also contemplate the nature of ETI's intelligence. Respected scientists introduced the first plausible non-humanoid ETIs. SETI's adherence to traditional assumptions, including humanoid ETIs, left the project increasingly disconnected from the broader ETI discourse.
The expansion of the ETI discourse began at roughly the same time SETI began; this timing proved unfortunate for SETI but was not entirely coincidental. Ironically, SETI itself helped inspire the change in the ETI discourse. By simply suggesting that ETIs might be sending us radio messages, SETI stimulated the curiosity of many about what those messages, and the intelligences that sent them, might be like.
The act of searching inspired questions about the nature of SETI's intelligence, but a historical transition in the field of experimental psychology provided the bases for developing new answers to those questions. The behaviorist model dominated the field during the first half of the 20th century. Around the same time SETI was launched, experimental psychologists began to favor the new, multi-disciplinary paradigm of cognitive science. Both SETI and cognitive science were products of the Second World War; the military effort produced the computer science and information theory at the conceptual core of cognitive science as well as the radar and the radio telescopes SETI used. The significance of the transition from behaviorism to cognitive science for the ETI discourse lay in the fact that, whereas behaviorism had little use for notions of "mind," the assumptions and methods of cognitive science gave potential contributors to the discourse a new vocabulary with which to discuss the cognitive structure, consciousness, and intelligence of an ETI in a scientifically rigorous way, and new tools with which to construct the first plausible non-humanoid ETIs.
The very existence of plausible non-humanoid ETIs posed a challenge to SETI because they made it increasingly clear that SETI searched for humanoid ETIs. More pointedly, three specific critiques of the SETI project emerged from the expanding ETI discourse. The Soviet CETI team was initially as enthusiastic about SETI-style searches as its American counterpart. Unlike the Americans, however, the Soviets took a closer look at the assumptions behind the search strategy and concluded that it would succeed only in the special case that the ETIs sending the messages were humanoid. They questioned SETI's ability to even detect that a message from non-humanoid ETIs was a message. The Americans responded to the Soviet critique with a fundamentally wishful assumption they christened "anti-cryptography": that any being intelligent enough to send us a message would be intelligent enough to make it easy for us to understand.
The evolutionists' critique compounded the Soviets' critique by asserting that the humanoid ETIs which SETI could detect were unlikely. The evolutionists concluded that the evolutionary path from the origin of simple life to human intelligence was too long and complex to be repeated again. Sagan tried to counter the evolutionists by positing a "quasi-ergodic theorem" based on the possibility of many possible paths to any given end state, such as humanoid intelligence. This argument smacked of deterministic thinking and the evolutionists ignored it. At Morrison's suggestion, Sagan turned the issue over to a probability theorist, who returned a verdict against Sagan. SETI's proponents nonetheless clung to their early assumption that the evolution of humanoid intelligence was inevitable once life arose. To do otherwise – to acknowledge the evolutionists' critique – would have been tantamount to acknowledging that the one type of ETI they did look for was unlikely.
The evolutionists' critique also inspired others to question SETI's assumptions and methods and, indeed, its very status as well-conceived science. Francis Crick accused Sagan of constructing flimsy analogies by extrapolating from only one known example – human intelligence – especially when we did not understand the evolutionary steps that led to that end state. The accusation amounted to a direct challenge of SETI's indispensable assumption of mediocrity, that humans are not exceptional. Sagan considered it axiomatic that one example of intelligent life implied others; Morrison and Drake went so far as to claim that only such analogies were prudent. Shklovskii delivered a decisive blow to the CETI project he fathered when he charged SETI-Science with inverting traditional scientific methodology: unlike more conventional science that began with observations and then devised theories to explain them and experiments to test the theories, SETI searched for observations.
Philosophers of science organized the third critique based on the expanding ETI discourse. Again using tools of the new cognitive sciences, especially linguistics, they questioned another of SETI's most important assumptions: uniformitarianism, or the claim that all intelligences evolve similarly because they evolve in response to similar conditions. These critics conclusively denounced uniformitarianism, and this time SETI's architects had no ready response. The challenge came at a particularly inconvenient time because NASA had just completed its Apollo and Viking programs and finally turned its attention to SETI. It was around this time, the latter part of the 1970s, that SETI proponents began to reposition their project, increasingly speaking of it as exploration rather than as scientific experimentation.
As a result of these critiques, then, SETI's scope seemed narrow, perhaps unduly narrow: SETI searched for messages from humanoid ETIs, which are unlikely, but might miss messages from non-humanoid ETIs. These issues played an important role in the withering of Soviet interest in CETI, even before NASA's SETI's project began in earnest. The American SETI team, on the other hand, adopted an essentially dismissive attitude toward these "nature"-based critiques. I believe there were three reasons for their reaction, and that these are best illustrated by contrasting the American and Soviet efforts.
First, the institutional platforms in the United States and Soviet Union were dissimilar, and the differences caused the Americans to respond differently than the Soviets to the opportunity of a SETI-style search. Specifically, institutional biases inclined the Soviets toward reflection and conducting their observations within a robust theoretical context, but inclined the Americans toward action. The endorsement of the Soviet Academy of Sciences was essentially both necessary and sufficient to obtain funding. The CETI team apparently felt it was in their interests to stick closely to the conventional methodology of scientific inquiry: they surfaced potential issues quickly, circulated them widely, and collaborated with colleagues whose expertise could complement their own. The U.S. SETI team, on the other hand, had to appeal, ultimately, to the American public for their funding and behaved accordingly; "selling" their idea took precedence over establishing it on the soundest possible scientific footings. They tried to keep attention focused on the outcome of a successful search rather than on the details of the search itself. They spent little time critically evaluating their assumptions, methods, or mission. Sagan's aggressive promotional genius was of more immediate value than deep insights into the project's conceptual soundness. Whereas the Soviet Academy of Sciences functioned as a scientific authority, the American National Academy of Sciences set a lower standard for its endorsement – plausibility – and functioned as an advocate on two important occasions in SETI's history: at its inception and when SETI hit the inflection point at which the "nature"-based critiques achieved a critical mass that could no longer be ignored by NASA.
Second, there is evidence suggesting that the Americans' dismissive attitude toward the expanding ETI discourse was the product of a conceptual blind spot about a being's cognitive structure, consciousness, and intelligence. This blind spot, in turn, might be explained by a variety of factors. The American scientists were culturally imprinted during their youths with the humanoid ETIs of the traditional ETI discourse; the Soviets, on the other hand, first thought about extraterrestrials as mature scientists. Moreover, many Americans dismissed any kind of ETI – let alone non-humanoid ETIs – as fanciful; the Soviet state philosophy, dialectical materialism, on the other hand, expected ETIs. Although both the Americans and the Soviets grew up in intellectual regimes strongly influenced by behaviorism to disregard concepts like a being's "nature" as unscientific, the Soviets were quicker to pick up the emerging tools of cognitive science and use them to identify defects in SETI's rationale. In particular, the Soviet CETI astronomers used the new vocabulary of cybernetics to discuss non-humanoid ETIs and the problems of communicating with them. Finally, the emerging segment of the ETI discourse dealing with ETI's "nature" was, simply, hard to spot. There was no formal American academic space in which to discuss these ideas, and the venues available in the popular culture – "hard" science fiction and popular expositions of ETI science – were clogged by the dominance of SETI-Science and SETI-ETI. One would have had to dig deep and wide to fit together the emerging vision of plausible non-humanoid ETIs.
There is also, on the other hand, evidence that the disregard of the "nature"-based critiques was not entirely the innocent product of conceptual blind spots. SETI's promoters occasionally played loose with the facts in ways that minimized the impacts of these critiques. They "packed" SETI conferences with friendly experts who confirmed that humanoid ETIs would inevitably evolve on earthlike planets. Despite the fact that many prominent evolutionists publicly questioned this assumption, their voice was conspicuous by its absence at SETI conferences. In his arrogation of Shklovskii's text Sagan essentially eliminated Shklovskii's inconvenient questions about the assumption of mediocrity. Billingham misused the concepts of evolution to justify conclusions that were suspiciously convenient. He and Oliver misreported the Soviets' position on the difficulty of communicating with ETIs in their Project Cyclops report, and engineered the official name change that deflected attention away from those same issues. The briefing prepared for the Congressional subcommittee that approved NASA's SETI funding was inaccurate and misleading; Billingham's SETI Program Office provided "assistance in obtaining information about NASA efforts in this field."
Third, the geopolitical context suggests possible explanations for the American SETI team's disregard of the mounting "nature"-based critiques. The SETI story was very much a product of the Cold War. SETI's most enduring legacy to date is its profound impact on Cold War popular culture. The American public displayed an immediate affinity for the search process, an act of listening simultaneously ultramodern in its use of Space Age technology yet premised on ancient values like patience, open-mindedness, and goodwill. The public was also drawn to the target of that process, as SETI's promoters held out the tantalizing prospect of learning from ETIs that both possessed "advanced" scientific know-how and exhibited "superior" virtue. The scientists who ushered in this powerful metaphor for an antidote to the Cold War all enjoyed some degree of renown; their chief spokesperson, Sagan, was arguably the best-known scientist of his day. Morrison and Sagan made active use of SETI to promote their anti-nuclear agenda by telling audiences that any messages they detected were likely to come from civilizations wise enough to negotiate their way through "technological adolescence," and challenging those audiences to join that club. Feeling the fair wind of an enthusiastic public at their backs, Drake and the other astronomers undoubtedly anticipated greater access to observation resources as a result of SETI. Both the immediacy and the vigor of the public's response were powerful signals to leave SETI just the way it was; there was simply no place in the vision they promoted for non-humanoid ETIs.
The geopolitical context probably exerted another important, but less public, impact on SETI's architects. They admitted to being personally alarmed by the nuclear arms race at their first conference, in 1961. There they argued that the most important determinant of the existence of ETIs was the Drake Equation variable L, or the longevity of societies; they also disclosed their belief that "fears that the value of L on earth may be quite short are not groundless." SETI's architects did not think about individuals and how they might construct reality because of their preoccupation with the dangerous ideological battle between superpower civilizations. Individual beings are eerily conspicuous by their absence from the SETI literature. All the SETI pioneers, the Soviets as well as the Americans, spoke of SETI as communication between civilizations, not individuals. It is quite possibly the case that "nature"-based critiques were simply too granular to command attention when they appeared.
Although the American SETI team appeared to be stuck in an increasingly anachronistic ETI discourse, NASA was not. Its public acknowledgment in 1979 that SETI searched for humanoid ETIs, which were unlikely, but not non-humanoid ETIs, which were possible, marked the onset of the inflection point in the project's history. NASA, with the concurrence of the NAS and the acknowledgment of the IAU, accommodated SETI's peculiar standing in the scientific community by conferring an unusual status on the project: SETI was "an imaginative, relatively low-cost gamble that could provide immense rewards in the event of a success." SETI was, in other words, a lottery ticket.
Amidst overt complaints in the IAU that SETI was "pseudo-science," SETI's relevance as a Cold War symbol faded with the dissolution of the Soviet Union. When presented with this third opportunity to do so, the NAS did not come to SETI's aid, and Congress abruptly and prematurely cancelled its funding for NASA's SETI project. The popular culture once again quickly reflected the public's changing attitudes. SETI was ridiculed in films and demoted in popular expositions of ETI science to a "belief," not unlike UFOs.
It is tempting to speculate that a fickle public abandoned SETI as one more relic of a Cold War ethos that produced more than its fair share of bizarrely conceived projects. However, that conclusion ignores the fact that cogent arguments had circulated for three decades about why SETI would not find a message because its scope was unnecessarily and arbitrarily narrow. SETI's founders gambled on public support, a bet that seemed like a good one at the time. In one sense they lost, given the withdrawal of funding after three decades of waiting. On the other hand, their careers hardly suffered as a result of their close association with a very popular project. The NAS inducted Morrison, Drake, and Oliver for contributions unrelated to SETI; Sagan was denied this honor and had to console himself with popular acclaim and great wealth. SETI enjoyed a long run as, in Shklovskii's words, pop science. By this point in SETI's history, however, its proponents had paid too little attention to the concerns expressed by the scientific community to now find institutional support in academia. Having redefined themselves as explorers rather than experimenters, SETI's architects turned to a source of funding traditionally associated with exploration – private patronage – and faded from the public view.
SETI's pioneers identified an exciting new way to look into the universe, but they chose to do so through an unnecessarily small keyhole. They behaved as though they felt threatened by the idea that ETIs probably evolved cognitive structures, consciousnesses, and intelligences that construct realities different from ours. To the extent that their fears stemmed from a concern that talk of something as bizarre as non-humanoid ETIs might cause potential funders to flinch, it is worth noting that the SETL project – of which SETI was thought to be a part – has recently found energetic new support precisely because of its willingness to engage the radically Other. SETL today contemplates extremophiles and their habitats that were, not too long ago, thought to be as unlikely as some of the non-humanoid ETIs that have been proposed.
The source of SETI's original appeal was the prospect it held for transforming the radically Other from a feared unknown into a source of great wisdom through patient listening. Our ability to imagine ETIs has expanded dramatically since SETI was first conceived. The scientific community marginalized SETI as it became disconnected from the ETI discourse that provides its context. Perhaps, as we celebrate SETI's Golden Anniversary, the current generation of SETI leadership can rekindle some of the project's original appeal by acknowledging the possibility of non-humanoid ETIs and inviting new experts to help them think about how to expand SETI's scope to embrace them.