1. Introduction
Ever since the dawn of civilization, human beings have been searching for their origins and their destinies. Philosophy, science, religions and even superstitions are part of the human quest for existential meanings and truth. Certain crucial questions about human life have preoccupied our ancestors: How did life begin? What is the purpose of life? What is the best kind of life? Does God exist? Do other kinds of life exist in the universe? Why must we suffer? Can we be immortal? What is the good? What is the essence of justice? What is human dignity? The human identity and the fulfillment of the human person are actually the primary concern of these intellectual questions that have challenged the greatest minds2.
In the quest for human origin, modern science has given us a partial answer – Human beings are part of nature incorporating a long dynamic evolutionary process governed by law and chance. This evolutionary worldview should be integrated with our religious beliefs so that we can acquire a deeper understanding about humanity and our relationship with God and nature. In fact, theology is faith seeking understanding and therefore, as with science, its contents should be reexamined whenever there is new supportive or incongruous knowledge. The exploratory nature of any theological investigations should always allow us to find new descriptions about the Christian faith as well as the reality and experiences of human beings. Although Christian theology is necessarily founded on historical revelation and religious experience, many scholars hold that it should be consistent with the physical reality discovered by scientists. The universe is a creation of God and what we find in nature should reflect the wisdom and the beauty of the same God who communicates with us through the incarnate Logos. St. Paul says plainly, “Ever since the creation of the world his invisible nature, namely, his eternal power and deity, has been clearly perceived in the things that have been made. So they are without excuse.” (Rom 1:20) In this paper, we will first show that the concept of the human person in the Bible is largely consistent with the findings of contemporary science. We will then investigate the basic ideas in the anthropic cosmological principle, a seemingly new design argument for the existence of God, and explore its implications for the theology of creation. We will illustrate that this modern anthropic principle is coherent with the doctrine of the Logos. In the light of the new discoveries in science, we will explore the possibility of the existence of extraterrestrial intelligence and its theological implications, trying to give a coherent picture of the evolving cosmos in the end. We will also attempt to reformulate the doctrine of original sin in the language of evolutionary biology, as an example to demonstrate the possible integration of modern science and Christian faith. Finally, we will discuss the role of the cosmic Christ in God's creation and the fulfillment of human life in our new cosmic picture. We will point out that creation and salvation are two interrelated concepts in the Bible. Jesus Christ, the Logos, is the manifestation of the divine creative work and the incarnation can be considered as part of the cosmic evolution that involves the direct participation of the Creator. The salvation of Jesus Christ is the continuous creation of God in the evolutionary perspective. Our participation in the creation leading to a new stage of evolution is part of the fulfillment of the divine creative work.
2. The Biblical View of Human Nature
In the Bible, particularly in Genesis, we can trace four features of the concept of human nature3, as outlined below4.
2.1 A unitary person, not a body-soul dualism
The Hebrew word 
(usually translated as soul) in the Old Testament and the corresponding Greek word 
in the New Testament refer to the inner self or the life principle in accordance with the whole person and they do not mean the immortal separable soul.5 The bible looks upon body and soul as different aspects of the same personal unity. Joel Green states clearly, “It is axiomatic in Old Testament scholarship today that human beings must be understood in their fully integrated, embodied existence. Humans do not possess a body and soul, but are human only as body and soul.”6 According to Oscar Cullmann, “the Jewish and Christian interpretation of the creation excludes the whole Greek dualism of body and soul.”7 In the Bible, there is no actual dichotomy between body and soul. The person is always regarded as an integrated embodied self. Lynn de Silva writes:
Biblical scholarship has established quite conclusively that there is no dichotomous concept of man in the Bible, such as is found in Greek and Hindu thought. The biblical view of man is holistic, not dualistic. The notion of the soul as an immortal entity which enters the body at birth and leaves it at death is quite foreign to the biblical view of man. The biblical view is that man is a unity; he is a unity of soul, body, flesh, mind, etc., all together constituting the whole man.8
In 1 Corinthians 15:38-58, Paul stresses the resurrection of the total person, but not of the immortal soul separate from a body. He affirms, however, the transformation of the body in the future life, which he describes as “the spiritual body” (1 Cor 15:44).
2.2 A Unique Creature in Nature
The first creation account in Genesis 1:1-2:4a clearly depicts humanity as part of nature, shaped with limitedness not unlike other creatures. All living things are related to one another, forming an interdependent life matrix. As the divine creation is good, the natural world has its own inherent value which is independent of human beings. Nevertheless, the Priestly tradition also asserts that only humanity is created in the image of God (Imago Dei):
Then God said, ‘Let us make man in our image, after our likeness; and let them have dominion over the fish of the sea, and over the birds of the air, and over the cattle, and over all the earth, and over every creeping thing that creeps upon the earth.’ So God created man in his own image, in the image of God he created him; male and female he created them. (Gen 1:26-27)
Of all the creatures, only man is able to know and love his creator. He alone is called to share in God's own life9. This is the fundamental reason that humanity is unique within the natural world and each human individual possesses the dignity of the person. Humans alone are free moral beings who can choose between good and evil and be responsible for their choices. They not only have the command over all the creatures but also have the privilege of speaking directly to God. They are responsible selves integrated with moral and spiritual capacities and bodily instincts. Although the biblical authors divided the creation of God into six days or periods10, they certainly did not intend to portray an evolutionary worldview to their readers. Nevertheless, the biblical descriptions of the similarities and differences between the human species and all the other creations are largely coherent with contemporary scientific findings.
2.3 The Social Self
“It is not good that the man should be alone.” (Gen 2:18)
As Green argues11, the biblical anthropology emphasizes the holistic and social character of human beings. For the Israelites, God’s covenant that created the unity of their nation was with one people, but not with a sequence of individuals. Moreover, in the Scriptures, individuals were always placed in the context of a community which has its own traditional anthology of sacred stories and rituals. God is concerned not only with the motives and actions of each individual but also with the integrity of the life of the community. Human beings are not independent individuals, but are related to one another as members of a family, citizens of a nation and children of the same personal God.'
The nature of the human person in the Gospel of Luke hinges on the understanding of Jesus' salvific ministry, which is essentially the major theme of Luke's writing. Luke's concept of salvation implicitly leads us to the meaning of authentic human existence. In Luke's narrative of Jesus'healing of the woman suffering from the hemorrhage (Lk 8:42b - 48)12, we can find a vivid depiction of a holistic and social anthropology. The healing of the woman whose sickness was socially distressing13 involves not only reversal of her physical malady, but also restoration of her place in the society as well as provision of new relations in the community of Go's people. This conception of the holistic and social character of the human person can also be found in other Synoptic writings. For example, in the Gospel of Matthew, cleansing a man with leprosy offers him new access to God and to the community (Mt 8:1-4, Lev 13-14); healing a paralytic is equivalent to forgiving his sins (Mt 9:2-8); extending the grace of God to tax collectors and sinners exhibits the work of Jesus as a healer (Mt 9:9-13); and restoring the sight of two blind men is linked to the manifestation of their faith (Mt 9:27-31). Similar accounts abound in the Synoptic Gospels, “where spiritual, social and physical needs are simply regarded as human needs.”14
2.4 The Image of God and the Fall
As mentioned earlier, humanity is created in God's own image. But what exactly is this image? And how much has man lost this image since Adam's fall? Although human beings as God's image have dominion over all other creatures, the meaning of the divine image should reflect the true nature of humanity but not just the wardenship of the natural world. In fact, the dominion of humanity over the creation on God's behalf should be exercised in a way that would reveal God's purposes for his creation. Moreover, being in the image of God the human individual is capable of entering into communion with other people, who as a family are called by grace to a covenant with God15. The nature of humanity therefore emanates from their relatedness to God as Creator. “The concept of the Imago Dei, then, is fundamentally relational, and takes as its ground and focus the graciousness of God's own covenantal relations with humanity and the rest of creation.”16
It is a well-known biblical story that Adam and Eve committed the first human sin by eating the fruit “from the tree of the knowledge of good and evil” (Gen 2:9). This story symbolizes the abuse of freedom and our first parents’ disobedience toward God, resulting in a break-up of the original harmonious relationship between them and their Creator. One of the tragic consequences of the first sin is the loss of the grace of the original holiness and justice that was a free gift of God. “Adam and Eve transmitted to their descendents human nature wounded by their own first sin and hence deprived of original holiness and justice; this deprivation is called the original sin.”17 By this first sin, “Death makes its entrance into human history” (Rom 5:12) and “human nature is weakened in its powers; subject to ignorance, suffering, and the domination of death; and inclined to sin.”18 All men and women are now born in a deteriorated state deprived of the original holiness and justice. Like a chain reaction, the descendents of Adam and Eve continued to sin19 and each person is affected by the sins of his or her predecessors and commits his or her own sinful acts. In other words, we are effectively exposed to “the sin of the world” (Jn 1:29) and we are all prone to sin and evil.
The fall of Adam and Eve affects us all by infecting us with this original sin, resulting in a loss of the image of God. The only cure to this inherited disease of human nature is baptism instituted by the new Adam, Jesus Christ, who has conquered death and is the only way to the eternal life of God. “Baptism, by imparting the life of Christ’s grace, erases original sin and turns a man back toward God.”20 The grace of baptism is another free gift of God superseding that of Adam and Eve. Through the first sacrament we express our recognition of the love and the presence of God. It is a symbolic action that reflects our acceptance of God's grace that has existed in our lives, even before we realize it. The washing and the cleansing by the waters of baptism symbolize the new life out of death, when one turns away from sin and evil and follows the Christian way of living. “As one man’s trespass led to condemnation for all men, so one man’s act of righteousness leads to acquittal and life for all men” (Rom 5:18). If one nonetheless is to ask why God did not prevent us from sinning, the best answer might be that “where sin increased, grace abounded all the more” (Rom 5:20)21.
The Yahwist creation narratives in Gen 2:4-3:24 reveal to us a great perception of the human condition that is actually an authentic experience for each of us. The fall story only provides a mythological reason for the current sinful human condition. It should be noted that the Yahwist, however, does not portray sin as something that is inherited or illustrate a doctrine of original sin. The second creation story cannot be understood in isolation and it must be grasped with other stories in the Scriptures. The ultimate meaning of the creation story or the fall of Adam and Eve can only be appreciated in the light of the death and resurrection of Jesus Christ. “The doctrine of original sin is, so to speak, the reverse side of the Good News that Jesus is the Saviour of all men, that all need salvation, and that salvation is offered to all through Christ.”22
The four features of human nature outlined above are to a great extent in harmony with the findings of modern science. In particular, current studies in neuroscience tend to support the view of nonreductive physicalism – the metaphysical position that “the person is a physical organism whose complex functioning, both in society and in relation to God, gives rise to higher human capacities such as morality and spirituality.”23 In his classic book on science and religion, Ian Barbour offers a nice summary:
It would be consistent with both the scientific and the biblical outlook to understand the person as a multileveled unity who is both a biological organism and a responsible self. We can escape both dualism and materialism if we assume a holistic view of persons with a hierarchy of levels. Some of these levels we share with all matter, some we share with all living things, some with all animal life, while some seem to be uniquely human. The person can be represented by the concept of the self, conceived not as a separate entity but as the individual in the unified activity of thinking, willing, feeling, and acting. The self is best described, not in terms of static substances, but in terms of dynamic activities at various levels of organization and functioning. In the biblical view, it is this integral being whose whole life is of concern to God.24
The new coherent understanding is that the human person is a multileveled unity emerging from the basic elements of the material world, participating in social activities with other persons, and being able to share in the eternal life of God.
3. The Anthropic Cosmological Principle 25
Before we delve into the creation concepts in the Scriptures, let us take a look at the modern cosmological theory that might be relevant to the creation ideas. In contemporary cosmology, the Big Bang is the most firmly founded model26 that describes the evolution of the cosmos from its early history to the present observable universe. In this model, the universe began about 14 billion years ago27 with a gargantuan explosion, from which all matter, energy, space and time came into being. Today scientists do not yet know how this explosion occurred. The scientific explanation of the Big Bang28 itself might require a complete marriage of the two most fundamental physical theories – general relativity and quantum mechanics. The unification of these two theories29 has actually been the final dream of many physicists30 since three quarters of a century ago. Without a complete theory, scientists can only give us some details about the evolving universe after it was about 10-43 seconds old31. In the Big Bang scenario, the universe has been expanding and its temperature has been falling ever since the extremely hot primordial explosion. One of the consequences of the cooling process is that matter was formed out of the hot radiation. Some of this matter later evolved into galaxies, stars, planets and even life and consciousness that we observe today in compliance with the laws of nature.32
For a long time, many great thinkers such as Thomas Aquinas (1227-1274) with his “Five Ways” have been trying to demonstrate the existence of God in a rational way. Surprisingly, modern cosmology points to an apparently new teleological argument and offers a great deal of evidence indicating that the universe has to be “fine-tuned” in order that life and consciousness can exist. The evolution of life depends on the laws of nature as well as the fundamental physical constants33 governing the interactions in the cosmos. Over the past few decades, scientists have discovered that the existence of life and consciousness is extremely sensitive to the delicate balance of these natural laws and physical constants. A slight change in the properties of elementary particles and the laws of nature would result in a lifeless universe34. Therefore there is an intimate link between the nature of the universe and our own existence. This so-called anthropic principle35 certainly has a profound philosophical implication for the biblical creation ideas.
The most frequently discussed scientific explanation for the many remarkable coincidences in the universe leading to the evolution of intelligent life is the multiple-universes idea, in which many universes could exist simultaneously or successively with different natural laws and values for the physical constants. Most of these universes are uninhabitable because of the inappropriate laws or physical constants. But a few out of many of them might harbor life because of the appropriate conditions. So it is not very surprising that we find our universe having some very special laws and physical constants because our universe is just the one with the favorable conditions, out of the many unsuccessful ones. There could still be a winner for the next lottery although the odds are extremely small. Nevertheless, I maintain that one might still imagine the existence of numerous universes, all of which have no life at all because there could be an infinite number of possible sets of physical laws and constants that are hostile to the existence of life. Large number of universes might not guarantee the existence of life. There could indeed be no winner for the next lottery if the odds approach zero.
Furthermore, as argued by John Leslie, the many-universes hypotheses are highly speculative and without any scientific evidence36. In fact, the major philosophical problem about the multiverse idea is that all these other universes are in principle unverifiable and hence non-falsifiable. The multiverse is indeed as elusive as God.
It seems more appealing to believe in a universe designed by a supreme creator whose existence is palpably supported by the religious experience in the human history. Does it follow that the anthropic principle provides evidence for the existence of God? This is not necessarily so. Our belief is not based on any scientific proof, but it is based on the revelation of God, as the New Testament emphasizes. However, one can contend that the new cosmology is consistent with the theistic worldview. Modern science shows that not only our universe is contingent, but also it has a high degree of rationality. Einstein said it well: “the most incomprehensible thing about the world is that it is comprehensible.”
4. The New Cosmology and the Logos
It is worth noting here that the Scriptures were written with an old cosmological conception. In fact, the cosmological view of the biblical authors was more influenced by their theological thinking than the natural observations in their times. The earth itself was already the whole static material universe. Above it were the stars and the heaven governed by God and below it were the abysses and the hell resided by the devils. In the age of science and technology, however, we should reformulate some of the theological contents in the Scriptures in light of the new scientific understandings about the cosmos. Biblical themes such as the creation, the providence and the salvation of God should be correlated with modern cosmological ideas that may bring new theological insights.
Contrary to the seven-day creation story in the Old Testament (Gen 1.1-2.3), cosmologists tell us that our solar system was formed out of the solar nebula about 4.6 billion years ago. The most primitive life on earth appeared about 3.8 billion years ago and later evolved into the diversity of life that we observe today.37 Homo sapiens were latecomers and first appeared about 400,000 years ago, following the Homo erectus that had their origins in Africa about two million years ago. Molecular biology and fossil discoveries have found that human beings and the modern African apes share 99% of their DNA, indicating that both species are descended from common ancestors38 who appeared about four to six million years ago. We are indisputably part of nature and, more significantly, have a long cosmic and biological evolutionary history. To develop a theology of nature that is compatible with the discoveries of modern science, the idea of the Logos is particularly important as it encloses the cosmic dimension of the incarnate Christ.
Rationality of the universe is the fundamental principle for science, without which scientific investigation becomes impossible. In the Prologue of the Fourth Gospel, John39 particularly speaks of the origin of Jesus to a cosmological extent. The parallel of the use of language between the Prologue and Genesis in the introductory verses is obvious and it connects the cosmic dimension of Jesus Christ, the Word made flesh, to the foundation of the divine creation. Jesus was with God in the beginning, before God’s creation and therefore before the existence of time, space and matter40. John commemorates Jesus as the Logos, or the Word of God, accentuating the hearing tradition of the Jewish community as well as the Johannine community: What we hear, see and experience now is the revelation of God. The Word that made the heavens and the earth is the foundation of all creation, as Paul has also proclaimed: “All things were created through him and for him. He is before all things and in him all things hold together” (Col 1:16-17). With a richer and deeper meaning than Genesis, John declares that Jesus not only is the source of all creation, but is the underlying rational principle of all existing things as well. In Greek, the term Logos also means the logic or the rational principle underlying the fundamental reality of the universe41. In terms of the Greek language, therefore, the creation and the rational principle in the creation were self-expressions of God who now reveals Himself as the Word, in whom we can find the true meaning of the divine creation.
The integration of the dual meanings of the term Logos clearly connects the Jewish creation ideas to the Greek philosophical conceptions about the ultimate operational rules of the universe at the time of the Johannine community. Moreover, it is significant that John identifies the Logos with God: “the Word was God” and personalizes the Logos with Jesus, as witnessed by John the Baptist and the Johannine community. The use of this special word Logos in the Prologue remarkably conveys to the readers the idea that Jesus was the divine creator who now brings salvation to his creation. In this respect, salvation may be regarded as a continuing process of the divine creation. In other words, creation and salvation are the same activity of God. For the Johannine community, God's creation had never stopped but had been continuing since the beginning of the cosmic history, particularly through the death and resurrection of Jesus and the receiving of the Holy Spirit that they had experienced. Jesus plainly said, “my Father is working still, and I am working” (Jn 5:17). Creation is not a one-time action but an on-going activity of God42.
5. The Rational and the Anthropic Principles
Does it follow that the anthropic principle is one of the self-expressions of the Logos? Scientists and theologians have not arrived at a conclusive answer to this question. On the one hand, one has to be cautious of taking too seriously the possible theological implications of the contemporary cosmological theories because scientific theories or hypothesis are by nature provisional. As mentioned earlier, we do not yet have a unified theory about the universe. In fact, according to Karl Popper43, we can never be sure about obtaining such a complete theory. If the current theory is to be replaced by a future one, we may then have to rethink our theological inferences.
On the other hand, what is philosophically significant is that our cosmos44 is rational and unified, whether we can eventually find a complete theory or not. The work of scientists is after all to study the natural laws reflecting the rational and unified beauty of the universe. Indisputably, the anthropic principle shows us the wonder of our cosmos. This aesthetic experience of scientific exploration was also the conviction of the Greeks or the Stoics in the first century.
Nevertheless, the Stoic philosophical view about the rational principle is static, and impersonal, whereas the Johannine experience of the Logos is dynamic and personal. John celebrates the pre-existent Logos as the life-giver and the light of the world. All things exist in him and through him. The Logos is the light that enlightens people and gives power to all his believers to become the children of God (Jn 1:12). In the beginning he was with God and now he becomes flesh and blood and tabernacles among us (Jn 1:14). The incarnation of the Logos brings glory to God and raises all existing things to a new stage of creation. In John's writings, the glory is always associated with the love of God; this is the “glory which thou hast given me in thy love for me before the foundation of the world” (Jn 17:24).
According to John, to be in unity and in love with God is embedded in the nature of creation.45 The incarnation of the Logos effectively marks a new level of existence for the creation. This is a new vision for the nature of the created cosmos that has been evolving from pure radiation46 to the complexity of life and intelligence.
6. Extraterrestrial Life
Before we turn to the discussion of the human condition in the evolutionary framework, let us now investigate the possibility of the existence of other intelligent beings in the universe in a scientific way. It is because the existence of extraterrestrial life will give us a new perspective on human nature within a cosmic context. The quest for the presence of intelligent life beyond the earth has its roots stretched back into antiquity47 and has a strong influence on both the scientific and the religious communities, serving as a good meeting point for the dialogue between them in the modern time. Christian theology should be implicitly involved in this ancient quest because it will naturally provoke us to ponder the relation between God and humanity and, in particular, the mystery of the incarnation of the Logos.
6.1 The Drake Equation
In the scientific context, the American astronomer Frank Drake48 proposed in 1961 his famous equation, N = R* x fp x ne x f1 x fi x fc x L , for estimating the number of technologically advanced civilizations in our galaxy that are presently capable of communicating with us (N). This so-called Drake equation contains a series of factors representing the probability of some major steps in the evolution of such civilizations. These factors are the average rate of formation of suitable stars in our galaxy (R*), the fraction of stars having planetary systems (fp), the average number of habitable planets per planetary system (ne), the fraction of those habitable planets on which life actually arises (f1), the fraction of such life-bearing planets on which intelligence develops (fi), the fraction of those intelligent-life planets that develop electromagnetic communications technology (fc) and, finally, the average lifetime of these communicating civilizations (L).
Scientists, however, do not have sufficient information and knowledge to determine, even approximately, some of these factors that have remained highly speculative ever since they were proposed. The actual value for N may be any number from zero to billions49. The contemporary advocates for a large value of N are mostly astronomers and physicists including Carl Sagan, Frank Drake and Philip Morrison50 who are very optimistic about the two biological factors f1 and fi whose values are simply taken to be one. Many leading evolutionary biologists such as Theodosius Dobzhansky, George Gaylord Simpson, Jacob Francois, Francisco Ayala and Ernst Mayr51 have opposed this oversimplification and argued that the development of intelligent life is extremely improbable even in the primate lineage. The evolutionist Owen Lovejoy explains clearly:
The evolution of cognition is the product of a variety of influences and preadaptive capacities, the absence of any one of which would have completely negated the process, and most of which are unique attributes of primates and/or homonids. Specific dietary shifts, bipedal locomotion, manual dexterity, control of differentiated muscles of facial expression, vocalization, intense social and parenting behaviour (of specific kinds), keen stereoscopic vision, and even specialized forms of sexual behaviour, all qualify as irreplaceable elements. It is evident that the evolution of cognition is neither the result of an evolutionary trend nor an event of even the lowest calculable probability, but rather the result of a series of highly specific evolutionary events whose ultimate cause is traceable to selection for unrelated factors such as locomotion and diet52.
The general consensus among evolutionists is that the emergence of intelligent beings involves a reasonably large number of improbable evolutionary steps53 that will make fi (and hence N) practically equal to zero and therefore the earth may be the only planet that harbors intelligent life in our galaxy or even in the entire universe. Consequently, as intelligent life actually exists on our planet, life of lower forms ought to be statistically plentiful in the universe. Although these different kinds of extraterrestrial life should expand exponentially within their environmental limits54, none of them may give rise to intelligence according to modern evolutionary theory. It is therefore not very surprising that astronomers will discover other primitive life forms in the solar system and other extrasolar systems in the future.
6.2 Carter's Argument
Based on the Copernican Principle55 one may still dispute that as intelligent life could actually develop on this planet in spite of the improbability in evolution, it should also happen again on other extrasolar planets that may be numerous in the universe56. To respond to this question, it is important to note that the observation of intelligence on earth is necessarily restricted by the weak anthropic principle57 (WAP) – what we observe in nature must satisfy the conditions required for our existence, otherwise we would not be here to discuss it. In other words, whether intelligence is everywhere or nowhere in this universe with the immensity of space and time58, we must find ourselves on this planet now. This is actually a consequence of the so-called ‘selection effect’. In fact, as first suggested by Brandon Carter59 in 1983, WAP supports the viewpoint of the evolutionists that the emergence of intelligence on a habitable planet is extremely improbable.
The basic idea in Carter's argument is to define three different time periods: tav (unknown) is the average time needed to evolve ‘intelligent observers’ on an earth-like planet, te ( 4x109 years) is the actual time taken for evolution to produce intelligent beings on earth, and tms ( 1010 years) is the lifetime of the sun which is classified as a G2 main sequence star60. Although we do not know tav, we would expect a priori that tav should belong to one of these three cases: (1) tav << tms , (2) tav tms and (3) tav >> tms. The second case should be statistically ruled out because it represents a very narrow part of the entire hypothesis space and there exists no physical relationship between the average time for evolution of intelligence and the lifetime of a main sequence star. Nevertheless, both case 1 and case 3 are not consistent with the observed fact that te tms (to within a factor of 2.5). This means that the actual observed time to evolve intelligence on earth (te) does not draw near to the average time needed to evolve intelligence on an earth-like planet (tav). Now if the first case, tav << tms, were true, we could have observed te tav with high probability. Therefore, combined with WAP, the observation that te tms implies strongly that tav >> tms and hence tav>> te. The fact that we observe te < tms is a necessary outcome of the WAP selection effect in spite of its minimal likelihood of occurrence. We must evolve successfully before the sun depletes its hydrogen fuel in the core, or else no observation could be made. In short, WAP inevitably leads us to conclude that the third case, tav >> tms, is most likely. This conclusion also implies that the existence of extraterrestrial intelligent life is highly improbable.
6.3 The Fermi Paradox
In their controversial book, Barrow and Tipler also develop the so-called space-travel argument against the existence of extraterrestrial intelligent life and come to the conclusion that
the probability of the evolution of creatures with the technological capability of interstellar communication within five billion years after the development of life on an earthlike planet is less than10-10, and thus it is very likely that we are the only intelligent species now existing in our galaxy.61
The basic idea of their argument, also known as the Fermi paradox62, is straightforward: If extraterrestrial intelligent beings exist and they possess a modest amount of rocket technology, they would colonize the entire galaxy for various reasons63 in less than 300 million years64 and should therefore have visited the solar system. Since we have not found them here on earth, this implies that they do not exist. The absence of evidence would actually be the evidence of absence.
6.4 Scientific Search for Extraterrestrial Intelligence
The discussions above are consistent with the null results (up till now) of over a hundred scientific projects in different parts of the world on searching for extraterrestrial intelligent life65. For example, Project Phoenix66, carried out during the late 1990s, was the most sensitive and comprehensive search for extraterrestrial civilizations. Using large radio telescopes, it scrutinized radio signals67 originating from the vicinities of about one thousand sun-like stars within a distance of two hundred light years from the earth. Yet no meaningful signals have been received. In fact, our earth has been broadcasting radio signals into space ever since the advent of radio and television technologies. The radio radiation from the earth is now more intense than that from the sun as seen by a distant observer in space. These terrestrial signals have reached a distance of 70 to 80 light years from the earth, revealing our presence to more than a thousand stars. As we have not received any responses thus far, we may conclude that no extraterrestrial civilizations exist within a distance of 35 to 40 light years, or if they exist they are not interested in replying to our signals.
As mentioned before, the existence of other intelligent beings beyond the earth would raise some interesting theological questions, especially in connection with Christology: Do extraterrestrial beings have original sin even though they are not descendants of Adam and Eve? Would there be multiple incarnations of the Logos in the other worlds?68 These questions unavoidably compel us to reexamine the doctrine of original sin and the meaning of the incarnation of the Logos, in particular with respect to the evolutionary worldview.