SETI: A Critical History: Cover
For millennia participants constructed the ETI discourse around a single question: whether ETIs exist. Contributors to the discourse did not question the "nature" of ETI's intelligence; they assumed it to be essentially like their own. SETI's architects conceived their project within this traditional ETI discourse. At almost that same moment of conception, however, the ETI discourse began to change dramatically. By adding a second question – about the form that ETIs' cognitive structures, consciousnesses, and intelligences might take – the ETI discourse suddenly stopped being simply a constitutive context for SETI and became, instead, a source of challenges to it. The possibility of plausible non-humanoid ETIs threw SETI's ability to communicate with, or even detect, ETIs into question.
Evolutionists from a variety of disciplines paved the way for this expansion of the ETI discourse by asserting that humanoid ETIs were unlikely, while at the same time pointing out that non-humanoid ETIs represented a credible evolutionary possibility. Ironically SETI itself bore some responsibility for the expansion of the ETI discourse. By simply suggesting a feasible way to communicate with ETIs, SETI inspired experts in a number of fields to wonder about the possible nature of the beings that might be composing and sending us messages.
The emergence of cognitive science played a major role in the expansion of the discourse to include the consideration of ETIs' "nature." Behaviorism dominated experimental psychology during much of the first half of the 20th century, and it shunned discussions of a being's "mind" as unscientific. Raised in that intellectual milieu, SETI's architects exhibited a blind spot toward questions about ETIs' cognition, consciousness, and intelligence. The multi-disciplinary field of cognitive science began to supplant the behaviorist paradigm around the same time SETI appeared, and its concepts and methods made a scientifically rigorous discussion of how beings construct realities possible for the first time. Scientists, science writers, and philosophers of science used these tools to imagine possible forms of extraterrestrial intelligence. At the same time, advances in a wide variety of fields, from entomology to weapons-systems research, provided what might be called a new analogical base from which to construct plausible hypotheses about ETI forms. To take a simple example, once scientists discovered that some insects "see" ultraviolet wavelengths, contributors to the ETI discourse analogized that ETIs might exist that are able to "see" different segments of the electromagnetic-radiation spectrum than humans and to imagine how doing so might produce consciousnesses and intelligences that differ from a human's.
Thus, at the same time the weight of expert evolutionist opinion increasingly came down against the possibility of humanoid ETIs, other experts discussed the possibility of non-humanoid ETIs with increasing rigor. Concern grew that SETI looked for an improbable kind of ETI, and would struggle to communicate with, or even detect, other kinds of ETIs.
Part II briefly reviews the significance of cognitive science for SETI and then examines three of these nature-based critiques in detail: those of Soviet SETI scientists, evolutionists, and philosophers of science. It closes with an overview of the plausible non-humanoid ETIs suggested; these stood as a kind of mute challenge to SETI's assumptions that ETIs are like us and are, as a consequence, relatively easy to communicate with.