Introduction

The human species is now undertaking a great venture that if successful will be as important as colonization of the land or the descent from the trees. We are haltingly, tentatively breaking the shackles of Earth—metaphorically, in confronting and taming the admonitions of those more primitive brains within us; physically, in voyaging to the planets and listening for the messages from the stars.

Carl Sagan, Cosmos

Carl Sagan promised us the stars, if only we will choose them. Like others before him, he cast the story of humanity as a developmental epic, evolving from animals, overcoming our beastly tendencies, and rising to take up our proper place in the heavens. He framed the present historical moment as adolescence, the first flush of adult awareness, power, and morality. His developmental narrative orients humans in space and time as well as in moral space—telling us what to value and what to choose. Moreover, it presents life in space as our highest good—spiritually as well as physically. Thus, it operates religiously as a doctrine of salvation. It identifies our best end and a means to get there. Meanwhile, it fails to operate biologically. The historically popular analogy between individual development and species evolution has been rejected by biologists. Continuing a long tradition of culturally scientific salvation stories, Sagan’s developmental epic lacks epistemically scientific backing, leaving followers of Sagan in an awkward position. What justifies Sagan-inspired hope for space science if not science itself?

Sagan’s Cosmos perspective promises salvation among the stars. Like traditional ascent narratives in ancient Greek philosophy and medieval Christianity, it values higher, ascended life over lower, Earth-bound life; it promises escape from the limitations of weight and embodiment, and it does so through metaphors of growth and development.1 The Cosmos perspective differs from other stories of salvation in its appeal to science, in this case, the science of evolutionary biology. In the words of Ann Druyan, “For Carl, Darwin’s insight that life evolved over the eons through natural selection was not just better science than Genesis, it also afforded a deeper, more satisfying spiritual experience” (Sagan 2007, 10). Appeals to evolution and development were not incidental to the perspective but an essential feature of its ethos. Science motivated his claims of truth. This justifies asking how Sagan crossed the is-ought gap (in arguing for space exploration) and whether he successfully crosses that gap by his own standards.

This article begins by asking whether we ought to read Sagan’s scientific works as religious texts and the developmental narratives as salvific. It then turns to how the developmental narrative operates ethically in Broca’s Brain, Cosmos, and Pale Blue Dot. Next, it looks at the history and character of the developmental narrative, before concluding with a discussion of alternative perspectives. Sagan’s technological and celestial optimism can be maintained if properly distinguished from the life sciences. The human epic can be viewed hopefully if set in a context that affirms its religious character and rejects both evolution and development as scientific justification.

Should We Read Sagan’s Writings as Religious Texts?

Sagan enjoyed a complicated relationship with religion. As a world-class science communicator, he reveled in engagement with religious believers on the big questions of human life: our place in the universe, our significance, and the choices we make. He embraced the language of cosmos, creation, and purpose. And yet, on precisely these issues, he felt science could save us from the perils of religious dogmatism and credulity. He cared deeply about fundamental questions of reality and value and, as such, regularly spoke on traditionally religious questions. Sagan’s writings operate sociologically and psychologically in religious ways. He self-consciously employed religious language and is read in religious ways. His Cosmos perspective is a narrative frame for human life that orients individuals within the universe morally as well as physically. Thus, we are justified in using tools appropriate to religious texts and religious doctrines. Sagan’s hopeful view of human development in space—and dismal view of the alternatives—operates as a doctrine of salvation, raising questions of what humans are saved from, by, and for.

Sociological Function

A common definition of religion invokes belonging, believing, and behaving. Religions orient believers within a community (to which they belong), provide shared language and concepts (in which they believe), and dictate shared practices (by which they behave). These themes occur repeatedly in Broca’s Brain, Cosmos, and Pale Blue Dot. Crucially, they advocate movement from scientific behavior to science-informed beliefs and common humanity.

Cosmos characterizes religion as proto-astronomy, emphasizing the role of both in creating worldview and situating humans within their environment. Of religious language, Sagan ([1980] 2013, 274) says, “These profound and lovely images are, I like to imagine, a kind of premonition of modern astronomical ideas.” “The chief difference between them and our modern scientific myth of the Big Bang is that science is self-questioning, and that we can perform experiments and observations to test our ideas” (Sagan [1980] 2013, 273). Cosmos also orients humans in time, exploring a developmental epic of evolution in which humans arise from animal forebears and aspire to a more elevated future, where elevation has spiritual as well as physical aspects (more on this later). Thus, Sagan sees himself inheriting the priest’s role of orienting humans ethically as well as physically. The difference is not one of function but of efficacy. He claims to do it better.

Pale Blue Dot spells out the process. Scientific behavior, by expanding human perspectives, improves both individuals and the species. Space science in particular opens the vistas of deep space and displays the fragility of human environments. “An emerging cosmic perspective, an improved understanding of our place in the Universe, a highly visible program affecting our view of ourselves might clarify the fragility of our planetary environment and the common peril and responsibility of all the nations and peoples of Earth” (Sagan 1994, 278).2 We are made of starstuff, but we are also the universe becoming capable of comprehending itself.3 And the more we comprehend the universe, the better off we are.4

Sagan does not neglect the inner cosmos of the subconscious. He has a great respect for investigations of human interiority and motivations. He spends most of his words on astronomy, his own area of expertise, but repeated references to human psychological development demonstrate the importance he places on this aspect of worldview. “And this two-pronged investigation into the nature of the world and the nature of our selves is, to a very major degree, I believe, what the human enterprise is all about” (Sagan 2007, 212). Our core identity as a species is fulfilled by looking inward as well as outward.5

A second approach to identity emphasizes human unity. “Pale blue dot” imagery, both in the book and in the popular imagination, leans into the idea of a common identity (as passengers) and a shared responsibility (as crew) on a small and fragile vessel (spaceship Earth). Space science reveals this truth literally through the image of Earth by the Voyager 1 spacecraft. Occasionally, this value of humanity transcends even scientific insight, as Sagan identifies the continued survival of humanity (or possibly rational life, capable of science) as the highest good. In discussing care for the planet, he says: “It seems to me this is the issue above all others on which religions can be calibrated, can be judged. Because certainly the preservation of life is essential if the religion is to continue. Or anything else” (Sagan 2007, 205).6

Belonging, believing, and behaving are inherently teleological. They do more than describe the state of humanity. They dictate its proper end. They orient us toward values and actions. Sagan’s view of space science goes beyond advocacy for science (as one good among many) toward worship, as the highest good and proper end of humanity.7 Science operates within society as public worship. It uncovers ultimate reality and orients us to a common highest good.8

Psychological Function

Moving from the role of science for society to the role of science for the individual, Sagan explicitly identifies his perspective with religion.

I would suggest that science is, at least in part, informed worship. My deeply held belief is that if a god of anything like the traditional sort exists, then our curiosity and intelligence are provided by such a god. We would be unappreciative of those gifts if we suppressed our passion to explore the universe and ourselves. On the other hand, if such a traditional god does not exist, then our curiosity and our intelligence are the essential tools for managing our survival in an extremely dangerous time. In either case the enterprise of knowledge is consistent surely with science; it should be with religion, and it is essential for the welfare of the human species. (Sagan, 2007, 31)

His Varieties of Scientific Experience, written for the 1985 Gifford Lectures on Natural Religion in Glasgow, consciously echoes William James’s Varieties of Religious Experience, arising from the Gifford Lectures a century earlier (1901–1902) in Edinburgh. Sagan’s definition of science fits well with James’s (2014, 53) definition of religion: “[T]he belief that there is an unseen order, and that our supreme good lies in harmoniously adjusting ourselves thereto.” Sagan might argue that the order is only as-yet unseen. It may be seen eventually through science. Of course, all religions promise eventual revelation. The key difference is epistemic—science uses empirical methodology—once again highlighting the preeminence of science among human activities.9

On the last page of Pale Blue Dot, Sagan identifies astronomy with religion in a more tangential way. “The pioneering psychologist William James called religion a ‘feeling of being at home in the Universe.’” (405) Sagan goes on to distance the two, saying old religions pretend the Universe is as they would have it be; true religion will embrace the real Universe.10 For Sagan, that is the job of science.

Use of Language

Sagan unapologetically uses religious language throughout his works. In her introduction to Varieties, Druyan reflects on the original Cosmos television series. “We were consciously going for a biblical cadence, words that would scope out the ambitious territorial range of our explorations in space and time” (Sagan 2007, xvii). The language of creation, myth, and purpose invites readers to view the material through a religious lens. This has rhetorical effect precisely because it presents to the reader an alternative to previous religious beliefs. In the introduction to Cosmos, Druyan again says Sagan set out to steal the thunder of religious fundamentalists (Sagan 2007, xviii).

Images of light and darkness provide one clear example of Sagan’s religious vocabulary. Druyan and Sagan’s 1995 book puts salvation clearly in the title: The Demon-Haunted World: Science as a Candle in the Dark.11 The powerful image conjures circling malevolent entities (from which one needs to be saved) and an opposing force (by which one is saved). The language parallels the opening lines of the Christian New Testament, where Jesus is presented as the light in the darkness. “What has come into being in him was life, and the life was the light of all people. The light shines in the darkness, and the darkness did not overcome it” (John 1:3b–5 NRSV). Nor is this an accident of enthusiastic speech or editorial imposition. In the opening of Varieties, Sagan (2007, 2) states that the universe is mostly darkness, but he is on the side of light. It would be hard to ask for a clearer religious comparison.

Reader Response

Readers continue to interpret Sagan in religious ways. Two prominent followers, Druyan and Neil DeGrasse Tyson, praise him in religious terms. Druyan’s introductions to Cosmos and Varieties were noted in the previous section. In the latter, she compares Sagan to the Hebrew prophet Joshua, Moses’s successor as leader of Israel (Sagan 2007, ix). Tyson’s 2013 introduction to Cosmos speaks of Sagan providing “knowledge shaped into wonder, the foundation of a Cosmos perspective on the world. Dare I assert that Cosmos wielded this power in ways that profoundly influenced how we would observe, interpret, and conduct our lives?” (Sagan 2007, xiii). These remarks make it clear that Sagan’s works do more than inform, they provide identity, shape thinking, and motivate action.

Concrete examples abound. The Ministry of Saganism identifies Saganism as a brand of scientism, naming Sagan the “apotheosis” of science presentation and the “high priest” of science.12 More common is a kind of quiet Saganism that identifies him as a fearless explorer, brilliant communicator, and inspiration. The careers of scientists such as Tyson, David Grinspoon, and Bill Nye owe much in spirit and practice to Sagan’s influence, which they proudly express. On April 6, 2023, Dr. Makenzie Lystrup was sworn in as the fourteenth director of the NASA Goddard Space Flight Center; she used Pale Blue Dot for her oath of office. Fulfilling ritual and ethical roles as well as linguistic and explanatory ones, the Cosmos perspective operates religiously in the lives of many scientists.

Sagan as Prophet

Sagan repeatedly contends he is not against religion per se. He rejects only irrational myths and practices. Reading Sagan as religious does not mean attributing dogmatic or supernatural beliefs. It opens the door for a close analysis of his words using methods honed through theology and comparative religion. It creates space to distinguish between his more careful methodological remarks (e.g., see for yourself) and his more expansive and value-laden narratives (e.g., spaceflight as human adolescence). I have great respect for Sagan. “His argument was not with God but with those who believed that our understanding of the sacred had been completed” (Druyan in Sagan 2007, xi). He regularly asserts the importance of humility. In this regard, he is much like Jesus. The test of a religious perspective is not the humility preached by the founder but the humility practiced by their followers.

Sagan challenges Christians to live up their ideals of love and humility. He holds up the stories they tell, particularly in scriptures, and the acts they perform. He then asks what impact they have on future generations of humans and the future of the Earth. Are the stories and practices consonant with the ideals? Sagan’s ideals warrant the same scrutiny. The Cosmos perspective is, in my opinion, worthy of study and sharing. And, as a worthy perspective, it is also worthy of critical analysis. I commend Sagan’s humility to those who follow Sagan’s soteriology. From the perspective of theology and comparative religion, these are clearly religious texts with a doctrine of salvation. They orient humanity within the cosmos—physical, historical, and moral. They provide a myth of where we come from and where we are going. And, critically, they identify harms from which we must be saved, choices we must make, and a way forward.

The Developmental Narrative

In orienting humanity in space and time, Sagan places science and spaceflight within a developmental epic. He describes an evolutionary childhood bracketed by two significant points, the origin of life (birth) and spaceflight (adulthood). Technological and ethical development for the species parallel physiological and psychological development for an individual. To understand spaceflight as adolescence, it will be necessary to unpack the broader developmental trajectory, or at least those elements Sagan provides for us.13 True to his epistemology, he draws on contemporary palaeontology and developmental psychology. More than a narrative device, the epic involves ethical improvement for the species. Humans literally rise above their biological limitations. It might sound odd to say that adulthood saves the individual from childhood. It is perfectly sensible, however, to speak of saving an individual from an early demise, or from perpetual childhood. In Sagan’s story, we are saved from a lower animal nature by science and for life in space.

One of Sagan’s favored moves is to compare humans to lower life forms, especially when speaking about potential alien intelligences. He refers to “climbing the phylogenetic tree from insect intelligence to crocodile intelligence to squirrel intelligence and [eventually] to dog intelligence” (Sagan 1979, 290). Elsewhere, he speaks of more advanced civilizations and species. This suggests a one-dimensional hierarchy of value on which species can be placed based on their intelligence, technological power, and moral insight. It entails a knowable, evolutionary trajectory from lower to higher life.

The concluding chapters of Broca’s Brain, Cosmos, and Pale Blue Dot each elaborate a developmental theme. They place the science of the book in ethical context, producing a moral take-home. In one sense, science and space exploration are the expected future for humanity, the next stage of development. In another sense, they are goods that must be chosen. Something in our past haunts us, something from which we must be saved. Sagan, ever keen on human agency, thinks we must save ourselves; no one else will save us. But, in true religious form, this salvation requires choice and sacrifice.14

Birth and Religion in Broca’s Brain

The final chapter of Broca’s Brain bears the title “The Amniotic Universe.” It argues for space exploration with a three-part analogy, comparing three processes: the transition of birth, the transition from religious to scientific cosmology, and the transition from Earthbound to a space-faring species. Working from the psychological theories of Stanislav Grof, Sagan suggests that all religion is, fundamentally, an attempt to make sense of perinatal trauma.15 Being expelled from the womb, we seek to understand our feeling of alienation. Sagan goes on to note a common religious narrative of creation as the mating of a male sky god and a female Earth god. Religion attempts to explain origins biologically and, in terms of personal experience, looks backward. This linkage marks religion as undeveloped, a conscious or unconscious association between infancy and an infantile worldview.

Sagan draws our attention to doctrines of judgment and salvation. “Might not the Western fascination with punishment and redemption be a poignant attempt to make sense of perinatal stage 2 [when uterine contractions begin]?” (Sagan 1979, 361). Doctrines of sin and salvation stand out as infantile. He asks if they are responsible for the oppressive power structures he considers so detrimental in the major religions: unquestioned authority, dogmatic belief, and coercive behavior. Science, on the other hand, requires curiosity, humility, and cooperation.

On the very last page, Sagan (1979, 368), Sagan comes to his moral, quoting the father of Russian rocketry Constantine Tsiolkovsky: “The Earth is the cradle of mankind. But one does not live in the cradle forever.” Humans should give up childish ways and embrace our destiny: mental growth in science and physical expansion in space.16 Both Earth and religion can, and ultimately should, be transcended as humans grow to adulthood.

Reptiles and Mammals in Cosmos

In the final chapter of Cosmos, Sagan presents a stark choice between two possible uses of modern technology: nuclear war and space exploration. Again, he relies on a narrative of growth, weaving individual development, social development, and species development together into an evolutionary epic leading to the stars. Again, he uses a three-part analogy: reptilian versus mammalian behaviors, reptilian versus mammalian structures in the human brain, and (reptilian) war versus (mammalian) love and exploration. The argument relies on intuitive links between physically cold-blooded reptiles and morally cold-blooded killers, as well as between both and “less evolved” species.17 He does not refer to mammals as more evolved than reptiles (carefully saying more recently evolved), but it is hard to avoid the comparison, especially in the context of “cosmic evolution” (Sagan [1980] 2013, 359). And, problematically, he describes human societies as having more or less mammalian behaviors and social structures. They are, by extension, more and less evolved societies.

Sagan draws on neuroscientist Paul McLean’s theory of brain evolution.18 The theory describes the evolution of mammalian brains in three stages, resulting in three layered structures moving outward from the brain stem. Humans share structures in the inmost layer with reptiles. In Sagan’s ([1980] 2013, 291) words, “Capping the brain stem is the R-complex, the seat of aggression, ritual, territoriality and social hierarchy, which evolved hundreds of millions of years ago in our reptilian ancestors.” The next layer, shared with non-primate mammals, houses other moods and emotions; the limbic system relates to touch, prosociality, and care for young. Outermost is that region unique to humans, the “cerebral cortex, where matter is transformed into consciousness . . . the point of embarkation for all our cosmic voyages” (Sagan [1980] 2013, 291). Here, we see spaceflight as adolescence in the broader context of cosmic evolution. Physical, moral, and, ultimately, technological progress play out across the stratigraphy of the human brain.19

Sagan uses this story to judge human cultures more and less advanced. Drawing on the work of developmental psychologists Harry and Margaret Harlow and James Prescott, he suggests a relationship between how children are treated in a society and how adults behave. More advanced mammalian behaviors can be encouraged by promoting physical displays of affection ranging from frequent touch to sexual freedom. More brutal and selfish reptilian behaviors result from childhood isolation and sexual repression. “Where physical affection is encouraged, theft, organized religion and invidious displays of wealth are inconspicuous; where infants are physically punished, there tends to be slavery, frequent killing, torturing and mutilation of enemies, a devotion to the inferiority of women, and a belief in one or more supernatural beings who intervene in daily life” (Sagan [1980] 2013, 350). More evolved societies produce more evolved individuals, and more enlightened individuals make for a more enlightened society.20

Sagan relies on individual mental development (towards cooperation and reason) recapitulating evolutionary change (towards more advanced life). Thus, the evolutionary epic plays out—and must play out—at three levels. Only at the individual level does development (in a biological sense) operate in a linear, normative progression toward adulthood. Only at the species level can we invoke evolution (in a biological sense) or compare such diverse groups as humans, mammals, and reptiles (and aliens). And yet, only at the level of cultures, societies, or civilizations can we discuss the types of social belonging, believing, and behaving Sagan wants to address. He needs to bring them together with a single developmental–social–evolutionary arc to set up the dichotomy that will be his key theme: life and death. Developmental psychology provides a linear teleology: from birth to adolescence. Evolution provides the scope: deep time. Linked, they provide an existential and social choice: forward to the stars or backward into barbarism; growth or decay; life or death. Space exploration and nuclear war represent that stark dichotomy. Like Moses, Sagan sets before us life and death and asks us to choose life.21

Technological Adolescence in Pale Blue Dot

In the final chapter of Pale Blue Dot, Sagan focuses on the existential choice for humanity—self-destruction or the stars. He starts with the Tower of Babel in the Torah and other narratives of hubris punished. He then says we need other myths, ones that urge us onward and upward. Our development has not (or should not) ended with the current level of technology; there is more. He praises Hindu, Gnostic, and Mormon doctrines of apotheosis—becoming gods.

The evolutionary epic is less visible, but it still motivates the argument. Rather than presenting multiple paths forward, Sagan presents his existential choice as one between growth (associated with science) and death. He explicitly rules out the possibility of sustainable constancy and argues for the importance of planetary colonies for long-term survival. Do not put all your eggs in one basket.

He sets forth the now common argument for exponential growth in technology. He provides back-of-the-envelope diagrams plotting the maximum velocity of human transport against year, showing an exponential curve from the stagecoach (1640) to the Voyager spacecraft (1977). “Even a modest extrapolation of our recent advances in transportation suggests that in only a few centuries we will be able to travel close to the speed of light” (Sagan 1994, 395). Surely, we will achieve faster-than-light travel within a century or two and “colonize the sky.”

This improvement is undoubtedly “growth” in a developmental sense and not just increase. Our descendants will be better than us.

It will not be we who reach Alpha Centauri and the other nearby stars. It will be a species very like us, but with more of our strengths and fewer of our weaknesses, a species returned to circumstances more like those for which it was originally evolved, more confident, farseeing, capable, and prudent—the sorts of beings we would want to represent us in a Universe that, for all we know, is filled with species much older, much more powerful, and very different. (Sagan 1994, 398)

Only mature species make it to the interplanetary stage, and maturity requires wisdom as well as power. Sagan even speculates that we may, in the distant future, become “Creators” in our own right, seeding and guiding life on other planets. Sagan presents cautions, but he does not shy from calling this project of colonizing other worlds a “telos” and “a sacred project.” It is a flowering of, if not a replacement for, traditional religion: space travel as salvation.

Contact

Among all of Sagan’s works, Contact most transparently and consistently presents the Cosmos perspective as religious and soteriological in character. The science fiction novel focuses on radio astronomer Dr. Eleanor “Ellie” Arroway, who receives alien transmissions instructing her to build a machine. Once built, the device proves effective for interstellar travel, bringing her and several companions to the center of the galaxy. There, they interact with aliens of advanced intelligence, who appear in the form of deceased loved ones. Their message: pursue science and space exploration as means toward species maturity. Upon return, the travelers find that no one on Earth believes them. The journey was, to outside observers, an instantaneous out-of-body experience. The travelers must rely on memory and faith in the face of opposition. Ellie describes the event as a conversion and her new perspective as “experimental theology” (Sagan 1986, 425–26).

The developmental narrative occurs throughout. Comparisons between animals and humans serve as a proxy for comparisons between humans and advanced aliens. The “ant is to human as human is to alien” analogy provides a recurring motif, reinforcing an evolutionary hierarchy.22 The Caretakers, a benevolent superior civilization, include diverse species from around the galaxy. They reveal a distinction between civilizations. More aggressive civilizations rarely achieve spaceflight and, even when they do, usually destroy themselves. “It’s in their nature” (Sagan 1986, 359). Civilizations that favor lovingkindness can grow in knowledge, wisdom, and power to join the galactic civilization, capable of galactic scale technology.23 The Caretakers help lower species in their path toward enlightenment, albeit favoring minimal intervention. They, in turn, aspire to follow in the footsteps of an even more advanced civilization. The Tunnel Builders left a message for the Caretakers to unravel, much as the Caretakers reached out to humans. Provocatively, near the very end of the book, Sagan asks whether there may be an even higher civilization to which the Tunnel Builders appear as worms—and humans as bacteria (Sagan 1986, 427). Contact may be read as an extended meditation on conversations between higher and lower life forms.24 Using words from Broca’s Brain (Sagan 1986, 368), “In some very real sense they will appear to us as godlike. There will be a great deal of growing up required of the infant human species.”

A Key to Sagan’s Ethos

The evolutionary epic provides a key to unlock Sagan’s ethical worldview. The proper end of humanity is growth as a species along a fixed trajectory toward greater knowledge, power, and wisdom. Humans have the option of turning off that path, but diversion brings destruction. The three elevations are coupled. To reject one is to reject the others. From Broca’s Brain in 1979 through Pale Blue Dot in 1994, the developmental narrative provides the ethical groundwork for decision-making in Sagan’s works. It justifies the importance of Sagan’s work in, and words about, space exploration. It motivates the decisions he asks readers to make—against (old) religion and for science, against war and for exploration, against stasis and for technological advance.

After Cosmos, Sagan intended to write a companion volume called Ethos that would explore his ethical perspective in greater detail. He took extensive notes but never wrote this book, though elements appear in The Demon-Haunted World and Varieties.25 I have chosen to focus on Broca’s Brain, Cosmos, and Pale Blue Dot because they are expressly popular science books. Sagan viewed the developmental narrative as a product of science. It had authority because of the biological evidence behind it. Many readers interpret Sagan’s works as scientific as opposed to religious in character—empirical rather than dogmatic, discovered rather than inherited—for this reason. They are written, sold, and read as scientific texts. This makes the soteriological reading more difficult, and yet, at the same time, more important. If the texts operate in a religious manner—orienting readers in the cosmos, identifying value (and disvalue), advocating choices, and calling for sacrifice—we should ask two key questions: whether the science supports the conclusions and, whether it does or does not, if we wish to adopt this perspective.

Development versus Evolution

Despite being told as an evolutionary saga, the tale is developmental. Biologists draw a clear line between the two kinds of change. Development and evolution were intertwined historically in problematic ways—ethical as well as scientific. Development describes a program of individual change from birth through adolescence, adulthood, senescence and eventually to death. The path is known. It is linear and normative. Failure to achieve adulthood is viewed as tragic; resistance perverse. Modern biology undergirds this teleology by invoking a genetic program designed by evolution, stored in genes, and carried out metabolically. Individual organisms do follow a preset path to adulthood. Natural selection optimizes them for survival in a given environment, within which the path to adulthood has been geared for survival and reproduction.

Evolution, on the other hand, describes the probabilistic divergence of species as they explore multiple environments and adopt (and adapt) diverse strategies. It is radial and nonnormative. The path is unknown, depending on chance events and various options. Early theories of evolution (in the nineteenth and early twentieth centuries) were developmental. They hung on ideas of God or nature “unrolling a scroll” of preplanned changes. They were teleological. They climbed the ladder of nature or, in the words of Lamarck, the “path to perfection.”

A similar idea dominated the human sciences at the time, which viewed human societies as developing/evolving toward a higher state. Auguste Comte’s law of three stages described the evolution of societies through theological and metaphysical stages to positive (or scientific) maturity. Similarly, the social Darwinism of Thomas Malthus, Francis Galton, Herbert Spencer, and others imagined natural selection bringing about better humans, often with a strong theological angle.

Darwin’s theory of evolution by natural selection provided a non-developmental lens through which to view evolution. Natural selection required neither preset telos nor normative character. The modern synthesis in biology, in the mid-twentieth century, explicitly ruled out progressive or developmental theories as too teleological. They had proved unfruitful and were replaced with random (properly stochastic) models that provided adaptation to local environments without any overall improvement or directionality.

The rise of Postmodernism in the mid-twentieth century also discouraged theories of social evolution. Germany—the most advanced technological society of the early twentieth century—behaved barbarically in World War II, and the pursuit of the atomic bomb proved the technology could be ethically horrific. Thus, confidence in social and species development was badly damaged. Postcolonial approaches later in the century further eroded the idea as the consequences of comparing societies on a single developmental ladder was seen to be complicit in the worst abuses of eugenics, communism, and colonialism.

Modern biologists reject the teleology of reliable evolution toward higher forms of life (Ruse 1996; Mix 2022). Butler (2009) expressly rejects the developmental narrative in McLean’s theory of brain evolution.26 In biological circles, evolution is no longer described in progressive or developmental terms. Because of the scientific and social excesses of the twentieth century, these ideas are not just avoided (as disproven) but actively rejected (as causing harm).

Sagan (2007, 157) cautions against such biological narratives in Varieties: “I think in the West it’s quite clear that there is a human or animal life-cycle model that has been imposed on the cosmos. It’s a natural thing to think about, but after a while its limitations, I think, become clear.” He clearly understood the challenges of viewing evolution through the developmental lens. His awareness, however, failed to reach the evolutionary epic that forms the core of his ethical reasoning in Broca’s Brain, Cosmos, and Pale Blue Dot. As discussed, the link between individual development and species advance is critical to the arguments he made there.

Blurring development and evolution provides a further problem. If species do develop analogously to organismal development, we should expect species senescence and death. Thus, the infinite, exponential progress Sagan imagines works neither under the developmental nor the evolutionary paradigms as modern biologists understand them.

A History of Progress

Sagan’s telos comes instead from the mythology of science. Although the developmental narrative (of evolution) was firmly rejected in twentieth century biology, that battle was hard fought, and the salvific characterization of scientific progress remains well entrenched. Its history and ubiquity can be seen broadly in discussions of science as well as narrowly in the fields of astronomy and astrobiology, which shaped Sagan’s thinking. David Noble (1999) documents the roots of scientific soteriology in medieval Christian millennial movements, focused on the role of humanity in bringing about God’s kingdom. Francis Bacon and other pioneers of science saw themselves participating in divine salvation. Science was restoring human dominion over nature just as Christianity was reconciling humans to God. It was a divine calling. Mary Midgley (1992) looks more closely at scientific soteriology in modern cosmology, focusing on John Barrow and Frank Tipler, Freeman Dyson, and Paul Davies. Each was influential in modern astrophysics and invested in a developmental narrative of human apotheosis. DeWitt Kilgore (2003) explores utopian ideas at the intersection of science and science fiction in mid-twentieth century writing. The genre of “hard” science fiction blends fiction and science with a progressive policy agenda deeply entwined with colonial narratives and projects. Similarly, John Traphagan (2021) discusses an evolutionary eschatology common to Star Trek and SETI.27

Developmental narratives of science as salvation were common among Sagan’s contemporaries. This should come as no surprise, noting the prevalence of progressive “evolutionary” thinking among scientists fifty to a hundred years earlier, particularly those interested in space travel and life beyond Earth. Marxist and positivist views among scientists have been well documented, but two specific scientists deserve special attention, being influential on Sagan’s thought. Biophysicist J. D. Bernal is best known for his pioneering work on x-ray crystallography and early promotion of space stations (or Bernal spheres). Before Sagan’s influential entry in Encyclopedia Brittanica, Bernal was the scientific authority trusted to expound on “Life.” He was deeply involved in discussions of the origin, future, and extent of life in the universe. His 1929 book The World, the Flesh, and the Devil sets forth a plan for science saving humanity for God-like maturity in space.28 The world is gravity, escaped with rockets; the flesh is the limitation of human bodies, escaped through mechanical augmentation; the devil is the human unconscious, escaped through Marxism. One generation earlier, Camille Flammarion was the preeminent popular science author. A French astronomer, he wrote prolifically to share the latest findings and promote citizen science. His books Lumen and Urania describe the transmigration of souls, growing in knowledge and wisdom as they move to more advanced bodies on more advanced planets orbiting other stars.29 Scholars debate how literally to take these accounts but, much like Contact, they set forth the evolutionary epic as both species development and a path to salvation. Straddling the divide between science, futurism, and fiction, Flammarion and Bernal modelled what it meant to be a popular science writer and discuss life in space.30

The developmental or progressive view of evolution was popular through the early twentieth century. It drew heavily on the language of biology, though it reflects a much older tradition of the scala naturae—or ladder of nature—connecting the lowliest creatures, through humanity and angels, to the throne of God (Lovejoy 2009; Ruse 1996; Mix 2018). Originating in biology, it was rapidly adopted by philosophers and theologians as a way of speaking about human improvement, growing holiness (sanctification), and possible growth to god-like power (apotheosis). Jesuit paleontologist and theologian Pierre Teilhard de Chardin may be the most well-known twentieth century proponent of the idea as both science and Christian doctrine. Biologists, however, moved decisively away from the idea, leaving it more ideology and history than science. Remnants of progressive biology lingered in neuroscience (as in McLean) and astronomy (as in Sagan) but disappeared from the discourse of mainstream and evolutionary biology.

Conclusion

If we continue to the planets and the stars, our chauvinisms will be shaken further. We will gain cosmic perspective. We will recognize that our explorations can be carried out only on behalf of all the people of the planet Earth. We will invest our energies in an enterprise devoted not to death but to life: the expansion of our understanding of the Earth and its inhabitants and the search for life elsewhere. (Sagan [1980] 2013, 362–63)

The Cosmos perspective on humanity places us within an evolutionary epic in which intelligent species emerge from a background of life, ubiquitous in the universe. Arising often from the material background, ecosystems occur on planets throughout the galaxy—and galaxies throughout the cosmos. A trait called intelligence—never fully explained but identified with radio telescopes and rocketry—elevates us above other species on Earth as uniquely adult or advanced. That trait, unambiguously adaptive regardless of environment and metabolic constraints, must arise from within ecosystems on a regular basis. It progresses uniformly through childhood, outgrowing violence, tribalism, social hierarchies, ritual, and theism, through to a scientific mindset culminating in radio astronomy and rocketry. Those particular developments open the doorway to a cosmic adulthood of interplanetary travel and, eventually, galactic colonization and mastery of worlds through technology.

And, though this is but one way of telling our story, it was for Sagan the only way. Science revealed the dangers of our reptilian impulses as well as our highest good—life among the stars, informed by the cosmos perspective, recognizing our common humanity (or a cosmic brotherhood of intelligent species) and valuing science above all else. Science produces truth. We are saved from the imaginary demons of our unconscious minds and from the very real harm they lead us to do to one another. We are saved by science and technology. And we are saved for life in space, contemplating the truths only science and space travel can provide.

In casting human evolution as an epic, Sagan has recapitulated a traditional narrative of salvation by ascent—physical, biological, technological, and moral—to the stars. But this developmental narrative fits poorly with modern biology. Evolution is less an epic and more a Picaresque dialogue between species and their surroundings, less Dante and more Don Quixote or Huckleberry Finn. The end is not known, ascent is not guaranteed, and the whole idea of salvation is called into question. This does not make the tale any less significant. We can be defined by evolution and exploration without claiming they make us better than our neighbors . . . or our ancestors. We can value the science while respecting that biology does not reveal a preordained path to perfection. It reveals instead an exploration of possibility.

A proper theological analysis would move on to judge the quality of the story. Does it accurately reflect the moral structure of the cosmos? Does it inspire in us, both individually and collectively, the right actions? Does it stir within us faith, hope, and love? In short, is it God’s story as well as Sagan’s? That analysis calls for a paper of its own, one that begins with a thorough exploration of the theologian’s ontological, epistemic, and axiological grounding.31 In short, it requires serious attention to metaphysics. As a scientist, Sagan has avoided this type of analysis but, insofar as his evolutionary epic is based in biology, it is no longer justified by science. Arguably, it was not justified biologically even at the time of publication. We must ask then where it comes from, what work it is doing, and whether we wish to accept it on those terms, whatever they may be.

Here, I wish only to identify the prevalence of this developmental narrative within Sagan’s writing and the immense ethical work it does therein. The cosmic perspective with its evolutionary epic justifies science in general and space science in particular, exploration in general and space exploration in particular. It values scientific knowledge over other forms of knowing, labeling religious perspectives as enemies of rationality, sociality, and human persistence. It asks believers to reject other forms of belonging, believing, and behaving as less advanced and aligned with death.

The Cosmos perspective operates as a narrative of salvation, addressing questions of highest value, that is, worship. It has consequences for both belonging and behaving in believers, as it calls them to identify more with more advanced individuals, societies, and perspectives and to actively choose them over less advanced alternatives. Quasi-biological ideas of evolution and development justify an anthropological divide—between lower and higher aspects of self—and a sociological divide—between lower and higher civilizations. Those divides cannot help but have ethical and policy consequences. Those consequences deserve close attention and cannot be glossed over as rhetorical flourishes, the adiaphora of science communication. They are central to the motivation of science authors like Sagan (in research and writing) and science readers.

By noting the soteriological function of Sagan’s texts, we can begin to analyze how they fulfill this function and whether we as readers are happy with the doctrine they provide. I share Sagan’s hope for the future, love of scientific exploration, and enthusiasm for human space travel. At the same time, I think these fundamentally religious propositions deserve scrutiny in the context of theology and comparative religion—fields honed to address such questions. Or perhaps a new field is needed. I am certain, however, that biologists—as empirical scientists—have neither the methodology nor the desire to answer these questions in this context. Insofar as they have, they have not come to these conclusions. For my own part, I will continue to set my hope on Christian ideas of salvation (rather than scientific), a love of science precisely because it reveals new and unexpected perspectives, and enthusiasm for space travel as pilgrimage rather than conquest. Science and technology serve purposes beyond themselves and our journey outward must transcend their bounds, just as we transcend the confines of our planet. I suspect Sagan could conceive of no greater legacy than to see his ideas actively debated, his perspectives compared with the latest scientific research, and hope for human progress lived out in critical thought and exploration.

Notes

  1. I refer to Sagan’s overall worldview as the “Cosmos perspective” following Neil deGrasse Tyson. Sagan himself referred to a “cosmic perspective.” [^]
  2. Elsewhere in Pale Blue Dot: “Planetary science fosters a broad interdisciplinary point of view that proves enormously helpful in discovering and attempting to defuse those looming environmental catastrophes” (Sagan 1994, 228). “Exploratory spaceflight puts scientific ideas, scientific thinking, and scientific vocabulary in the public eye. It elevates the general level of intellectual inquiry. The idea that we’ve now grasped something never grasped by anyone who ever lived before” (Sagan 1994, 281). He concludes that the discovery of alien intelligence would be “the last of the Great Demotions” following those of Copernicus, Charles Darwin, and Sigmund Freud (Sagan 1994, 365). [^]
  3. “For we are the local embodiment of a Cosmos grown to self-awareness . . . starstuff pondering the stars” (Sagan [1980] 2013, 364). [^]
  4. Note the similarity to Aristotle’s eudaemonia, in which the rational soul is fulfilled in contemplation of contemplation itself. Sagan has introduced a similar precept but applied it to the universe and the human species as well as individuals. He has also specified natural science as the highest form of scientia or knowing more generally. On the contraction of scientia from a way of being to a way of knowing, see Peter Harrison’s Territories of Science and Religion. Sagan expands the idea outward again. [^]
  5. Sagan echoes J. D. Bernal’s more explicit soteriology in The World, the Flesh, and the Devil: An Enquiry into the Future of the Three Enemies of the Rational Soul. The “world” represents the shackles of gravity, from which we are saved by rockets and space stations; the “flesh” represents the limits of animal bodies, from which we may be saved by cybernetic augmentation; and “the devil” represents the unconscious, from which we are saved by Marxism. Sagan may not be drawing on Bernal for his solutions, but he is clearly in the same lineage—both influential astrobiologists and science popularizers, writing on space exploration and the origin of life. Neither hesitated in speculating on the religious function of space science. [^]
  6. For more on the religious context of pale blue dot anthropology, see Lucas John Mix (2016). [^]
  7. Etymologically, worship shares a root in Saxon with worth and indicates the subject is of very high, perhaps highest, worth. [^]
  8. “If we continue to the planets and the stars, our chauvinisms will be shaken further. We will gain a cosmic perspective. We will recognize that our explorations can be carried out only on behalf of all the people of the planet Earth. We will invest our energies in an enterprise devoted not to death but to life: the expansion of our understanding of the Earth and its inhabitants and the search for life elsewhere” (Sagan [1980] 2013, 362–63). [^]
  9. Druyan, citing Gottfried Wilhelm Leibniz, suggests that in religious epistemology, God is a wall that stops further questions (Sagan 2007, 15). For more on historical shifts in the definition of religion and James’s place in this process, see Kevin Schilbrack (2022). [^]
  10. At the surface level, the distinction between old religion and astronomy has no teeth. Sagan is claiming knowledge of the real Universe for neither religion nor astronomy. This is a curious move for the last page of a book whose authority rests squarely on the author’s claim to have astronomy-based knowledge of the real Universe. The distinction, then, rests on Sagan’s epistemology: religious pictures are inherently dogmatic and incapable of change while astronomy progresses. Sagan must believe that science has, in some sense, delivered in a way that promises future knowledge. [^]
  11. Sagan and Dryan (1996). [^]
  12. https://ism.co/saganism/. [^]
  13. Sagan refers to early space flight as “planetary adolescence” in Pale Blue Dot (372) and “technological adolescence” in Varieties of Scientific Experience (115). More commonly, he simply refers to advanced civilizations. “We define an advanced civilization as one capable of radio astronomy.” (Sagan [1980] 2013, 315) “We must be the most backward technical society in the Galaxy. Any society still more backward would not have radio astronomy at all.” (Sagan [1980] 2013, 326) Thus we are just barely adult or advanced. He takes for granted that both rocketry and nuclear power would be contemporaneous discoveries for a civilization. A similar line of reasoning can be found in Varieties (115–18). [^]
  14. Mary Midgley (1992, 15) notes how science talks and books can promote salvation narratives in their introduction and conclusion. They escape critical analysis, being viewed as merely instrumental to communicating science. These narratives, however, motivate readers and often remain with them long after the scientific details are forgotten. “Scientific reviewers, when discussing writings of this kind, often treat the myths as a side-issue. Concentrating on what is acceptable as science, they expect the rest to fade away harmlessly into the general culture. But it does not necessarily do this. It can hang around like a fog, changing the atmosphere of thought and influencing ideas quite strongly. It tends to be the part of the book that people remember. In particular, it can be expected to have a strong effect on students” (Midgley (1992, 15). [^]
  15. “All successful religions seem at their nucleus to make an unstated and perhaps even unconscious resonance with the perinatal experience” (Sagan 1979, 363). “I do not propose that theology is physiology entirely. But it would be astonishing, assuming we really can remember our perinatal experiences, if they did not affect in the deepest way our attitudes about birth and death, sex and childhood, on purpose and ethics, on causality and God” (Sagan 1979, 365–66). [^]
  16. Sagan echoes Biblical language of spiritual growth. “I fed you with milk, not solid food, for you were not ready for solid food. Even now you are still not ready, for you are still of the flesh” (I Corinthians 3:2–3a NRSV). “When I was a child, I spoke like a child, I thought like a child, I reasoned like a child; when I became an adult, I put an end to childish ways” (I Corinthians 13:11 NRSV). [^]
  17. These links are not based on modern biology, nor even the biology of the mid-twentieth century when they were written, as will be discussed later. They rely on late-nineteenth century theories of progressive evolution, which had already been scrubbed from biology but remained popular among psychologists . . . and astronomers. [^]
  18. See Sagan ([1980] 2013, 291); also see Ann B. Butler (2009) for discussion of the theory. Butler notes in the abstract, “While this model has been enthusiastically adopted by some neuroscientists, particularly those with interests in psychiatry, it has been dismissed as evolutionarily incorrect and of no heuristic value by those in comparative, evolutionary neurobiology.” [^]
  19. McLean and Sagan echo the tripartite souls of antiquity and the Middle Ages, with the lowest, most selfish, and most physically oriented soul (appetitive or vegetative) fighting a socially oriented middle soul (spirited or animal), both controlled by a rational soul in humans. For more on the history and influence of tripartite souls, see Mix (2018). [^]
  20. Sagan reiterates his argument in Varieties (2007, 173): “[Prescott] concludes that all cultures in which the children are hugged and the teenagers can have sex wind up without powerful social hierarchies and everybody’s happy. And those cultures in which children are not permitted to be hugged because of some social ban and a premarital adolescent sexual taboo is strictly enforced wind up killing, hating, and having powerful dominance hierarchies.” Here, he is more direct in stating that theistic societies are the extreme case of (reptilian) dominance hierarchy, leading to a repression of touch and sexuality, causing their members to “torture their enemies” and “brutalize their children.” [^]
  21. Cp. Deuteronomy 30:19 [^]
  22. Pages 9, 37, 307, 361, and 427. Monkeys fill a similar role on page 313. [^]
  23. Type III on the Kardashev scale. [^]
  24. This is not a new genre. Emmanuel Swedenborg, founder of the New Church, wrote of such conversations in Planets in Our Solar System and in Deep Space, their Inhabitants, and the Spirits and Angels There (1758, republished as Other Worlds in 2018). This work is counted as scripture among Swedenborgians, who have been divided on how literally it should be interpreted. Subsequent works are usually classed as science fiction, albeit with a very high philosophical/theological content. Examples include Olaf Stapledon’s Star Maker (1937), C. S. Lewis’s Space Trilogy (1938–45), and more ambiguously, Ursula K. LeGuin’s Hainish Cycle (1969–94). [^]
  25. Sagan’s notes can be found in the Seth MacFarlane collection of the Carl Sagan and Ann Druyan archive (1860–2004) at the Library of Congress. [^]
  26. “The triune brain hypothesis, by essentially dismissing interest in pallial elaboration within the sauropsid line, errs by instead promoting the scientifically contradicted but still widespread popular view of a scala naturae, a linear ranking of animal taxa, with fish near the bottom, reptiles not much higher, nonhuman mammals higher and ranked in sequence (such as rat-to-cat-to-monkey), and with humans at the top” (Butler 2009). [^]
  27. “In this article, I am interested in exploring the scientific search for extraterrestrial intelligence (SETI) as a practice of imagination expressed via an evolutionary and moral eschatology in which intelligent species are saved as a result of perceived long-term benefits that come with progress” (Traphagan 2021, 120). Traphagan borrows the term evolutionary eschatology from an earlier article on religion in Star Trek by by Gregory Peterson (1999). [^]
  28. J. D. Bernal (2017). The trio of world, flesh, and devil is traditional Christian language describing the temptations of Jesus in the wilderness in Matthew 4:1–11 and Luke 4:1–13. Viewed as enemies of the soul, they describe worldly concerns, bodily concerns, and the worship of Satan or other spirits. [^]
  29. Camille Flammarion (1890, 2002). [^]
  30. For more on the deep, entwined history of religious, scientific, and science-fictional accounts of interplanetary travel, see Mix (2022). That article was inspired and informed by Sagan’s own notes on the influence of works like Lumen and Anatomy of Melancholy on his thinking. [^]
  31. Ontology addresses the qualities of being—what is. Epistemology tackles how we understand where knowledge comes from. Axiology covers principles of good and bad. [^]

References

Bernal, J. D. 2017. The World, the Flesh and the Devil: An Enquiry into the Future of the Three Enemies of the Rational Soul. Brooklyn, NY: Verso.

Butler, Ann B. 2009. “Triune Brain Concept: A Comparative Evolutionary Perspective.” In Encyclopedia of Neuroscience, edited by Larry R. Squire, 1185–93. Cambridge, MA: Academic Press.

Flammarion, Camille. 1890. Urania. Translated by A. R. Stetson. Boston: Estes and Lauriat.

Flammarion, Camille. 2002. Lumen. Translated by B. Stableford. Middleton, CT: Wesleyan University Press.

James, William. 2014. Varieties of Religious Experience: A Study in Human Nature. Project Gutenberg. https://www.gutenberg.org/cache/epub/621/pg621-images.html.

Kilgore, De Witt Douglas. 2003. Astrofuturism: Science, Race, and Visions of Utopia in Space. Philadelphia: University of Pennsylvania Press.

Lovejoy, Arthur. 2009. The Great Chain of Being. New York: Routledge.

Midgley, Mary. 1992. Science as Salvation: A Modern Myth and its Meaning. New York: Routledge.

Mix, Lucas John. 2016. “Life-Value Narratives and the Impact of Astrobiology on Christian Ethics.” Zygon: Journal of Religion and Science 51 (2): 520–35.

Mix, Lucas John. 2018. Life Concepts from Aristotle to Darwin: On Vegetable Souls. New York: Palgrave MacMillan.

Mix, Lucas John. 2022. “Decoupling Physical and Spiritual Ascent Narratives in Astronomy and Biology.” In The Institutions of Extraterrestrial Liberty, edited by Charles Cockell, 233–53. Oxford: Oxford University Press.

Noble, David F. 1999. The Religion of Technology: The Divinity of Man and the Spirit of Invention. New York: Penguin.

Peterson, Gregory. 1999. “Religion and Science in Star Trek: The Next Generation: God, Q, and Evolutionary Eschatology on the Final Frontier.” In Star Trek and Sacred Ground: Explorations of Star Trek, Religion, and American Culture, edited by Jennifer E. Porter and Darcee L. McLaren, 61–76. Albany, NY: SUNY Press.

Ruse, Michael. 1996. Monad to Man: The Concept of Progress in Evolutionary Biology. Cambridge, MA: Harvard University Press.

Sagan, Carl. 1979. Broca’s Brain: Reflections on the Romance of Science. New York: Ballantine Books.

Sagan, Carl. 1986. Contact. New York: Pocket Books.

Sagan, Carl. 1994. Pale Blue Dot: A Vision of the Human Future in Space. New York: Random House.

Sagan, Carl. 2007. The Varieties of Scientific Experience: A Personal View of the Search for God. New York: Penguin Books.

Sagan, Carl. (1980) 2013. Cosmos. New York: Ballantine Books.

Sagan, Carl, and Ann Druyan. 1996. The Demon-Haunted World: Science as a Candle in the Dark. New York: Random House.

Schilbrack, Kevin. 2022. “The Concept of Religion.” In The Stanford Encyclopedia of Philosophy, edited by Edward N. Zalta. https://plato.stanford.edu/archives/sum2022/entries/concept-religion/.