The Problem of Evolution as Seen by Theology
Because and to the extent that an evolutionary understanding of the world is one of the basic elements of today's conception of the world and one that does not harmonize completely with the traditional Christian understanding of the world, this problem must be addressed here.
The Methodological Point of Departure in the Theological Formulation of the Question
If one proceeds from the assumption that an evolutionary origination of the biosphere as a whole from the "mere" material world is likewise one of the elements of this evolutionary conception of the world, that "creation" of living being does not actually mean an intervention of God as a factor which can be located on a definite individual point of time in the history of reality, then for the theologian the question of the evolution of living being and the idea of a universal evolutionary development of the cosmos come down ultimately to one and the same question.
If in what follows we do not make a sharp distinction between the question of the development of the world as a whole and the question of evolution within the biosphere, that need not necessarily mean a reproach for the theologian. We are proceeding from the assumption that it is correct that there is a development which determines the entire cosmic reality and continues on through it. Our only question is whether a theologian who is against this has to raise an objection in the name of Christian faith. Whether this assumption is really correct; whether it has to be restricted; for what areas of universal development of this kind natural science can offer solid arguments and for what areas it cannot; what more precise kinds of "mechanisms" must be presumed and can be demonstrated for the individual stages of development: all of these are questions primarily for the natural scientist and, at least at the outset, lie beyond the competence of the theologian.
Methodologically, then, theologians have the right to presume the most extreme positions of evolutionary thinking (provided these make some degree of sense and do not actually constitute manifest metaphysical disregard for the boundaries on the part of the natural sciences). Then they ask themselves whether they can live with these positions. Theologians do not have to defend these positions themselves, since that is the business of natural scientists when espousing these extreme positions (which certainly is not always the case pure and simple). The theologians' position , then, is always a hypothetical one: if the exponents of the natural sciences maintain this or that, then ...
In answering this question we are going to try to forge a link between theology and the basic concepts of an evolutionary "world view," as daring as this may sound. It is of course obvious that this attempt is being made only because such a world view exists. But this does not alter the fact that theologians with their data and their assumptions can try on their part to have the way for an understanding of evolution and thereby determine whether evolution is compatible with the positions of theology.
Belief in Creation as the Transcendental Experience of the Origination of All Being from Absolute Being
Theologians proceed from the assumption that absolutely everything that is not God is created by one and the same God. This God they recognize as absolute spirit, pure meaning, intelligibility, and love, even though in all these affirmations they know that this God is above everything that exists or can be conceived of outside himself, that he is infinitely sublime and therefore they know that all affirmations about him become lost in his incomprehensibility. Everything that is, therefore, must bear the stamp of origin of this one primordial ground of being; everything must have an ultimate unity and community. The postulate of an ultimate unity of the whole world which cannot be resolved into a definitive, ultimately unthinkable disparity of several worlds, and of an ultimate spiritual nature which manifests itself in intelligibility, and of a being present to itself even though it admits of the highest degrees of differentiation, is implicit in the belief in creation. Materiality must be understood as the lowest stage of this spirit (even when this may perhaps be irrelevant to the pure natural scientist). Otherwise materiality cannot be conceived as originating from an absolute spirit, since this spirit cannot create something that is absolutely disparate from itself. Moreover, this spirit cannot form its creation into a materiality which would in an eternally unrelated way coexist side-by-side with it. Many in antiquity tried to explain the nonspiritual nature of the material world in this way.
If (by way of anticipation) we conceive created reality as manifold and yet one, that is, if we must assume an ultimately intelligible relationship of the individual realities of the world, then this relationship of the individual realities to one another cannot be conceived as anything but final, that is, as an interrelationship that has been ultimately intended and planned. It is not required that this finality of the individual realities of the world can always and in every case be discerned in a clear-cut way in the individual realities themselves with the limited modes of cognition available to natural science. This finality is already implicitly contained in the transcendental experience of the origination of all being from absolute being (and here, without difficulty, we may identify this experience with belief in creation). Elements of finality which come to our attention empirically may by all means be integrated into this transcendental experience of finality, since accident, strictly speaking, is no basis of understanding at all, but only points to the fact that in a limited area of understanding a reason cannot be found why this or that happens in this way and not some other.
Divine Causality: On the Ontology of the Relationship between God and What Is Created
God created finite beings. How can these be conceived in themselves, in their unity among one another, and in their relationship to God? These three questions must be considered in their corresponding unity. First of all, the individual being's relationship of origin from God is not a relationship effected at some time previously "in the beginning," but is, rather, the single creation and the "preservation" (to use the traditional expression) in equal reference to the temporal being and its temporality. This touches upon a difficult point in the traditional doctrine of God. This relationship of a created being to God can on the one hand be identified with the reality of this being; in an idea of creation which rejects every form of pantheism one may not say that God himself is an inner constitutive element of a created being. But in this affirmation theologians must exercise caution for theological reasons which have nothing to do with natural science.
For theologians recognize in the theology of grace and in the beatific vision a relationship of God to a creaturely reality in which reality God's own being is the quasi-formal cause and not merely the external efficient cause of a determination of the finite being. This theological datum already indicates that an efficacy of God through himself and not through a created mediation must be rejected as a pantheistic view only if God at the same time be conceived as an inner essential constitutive element belonging to the essence of the finite being. The distinction between God and creature which rejects pantheism therefore does not exclude a determination of a finite being by God himself as such, a determination which can no longer be adequately subsumed under the category of an "ontic," transient efficient causality. In a more profound ontology concerning the relationship of God's absolute being and finite being, which is being continuously constituted by God, one could show that the example from which we have just proceeded (uncreated grace and the beatific vision) does indeed imply an essentially supernatural relationship to God , accessible only through revelation, but that on the other band this relationship always and everywhere is nevertheless valid in an analogous way for the relationship between God's absolute being and being which originates from him.
This relationship cannot be grasped solely by just subsuming it under the general category of an efficient causality, such as otherwise exists between two finite beings which are already distinct from one another prior to such a causal relationship of a particular kind. The reason why this is not possible is that divine causality does not presuppose the distinction between God and creature, but itself establishes this distinction and precisely in so doing keeps it with itself in a unique way. Understandably the ontology of the relationship between God and what is created cannot be further developed and established here. It must, however, be emphasized that this singular relationship between absolute being and finite being, which is not really taken into consideration by a superficial theology of creation, is a subject which belongs to a transcendental knowledge of the origination of created being from absolute being, just as metaphysics is something aprioristic to the knowledge of natural science, is not part of this knowledge as such, and cannot be treated thematically in it. The important thing for the question of evolution in what has been indicated here is simply the plain sentence that the determination and events of a finite being are subject to the constant "pressure" (if one may use this term) of the divine being. This "pressure" is not one of the essential constitutive elements of a finite being. It can, however, always make this being into something more than it is "in itself, " or, as the case may be, it is that which in the first place makes the finite being what it is. For metaphysical knowledge this "pressure" is a given; for a purely ontically a posteriori knowledge, which is that of the natural scientist, it cannot be discerned.
What is meant by this will become clearer when explicit consideration is devoted to a "being in the process of becoming ." Then it must become clear that its character of being capable of becoming, which is no mere passive condition, ultimately in an ontological way can only be made comprehensible by this relationship of God to the finite being, without this relationship being, for its part, an individual ontic phenomenon.
On the Compatibility of the Teachings of Evolution and the Christian Conception of the World
Again we proceed from the a posteriori experience of natural science as it exists or is interpreted in the general and the particular theory of evolution. This theory states that all observable phenomena of the world which are accessible to the natural sciences are interrelated, that the world has undergone a development. Whether this development had a meaningful (final) direction from the outset and whether or not it continues to have one; what, exactly, such statements really mean; what part accident plays in a development of this kind, and what accident means–on these things and many others connected with them the natural sciences themselves are not in agreement. Nor has agreement yet been reached concerning the more precise mechanisms of biological development in particular, nor on the question as to what extent a continuous connection in the development of living being can be assumed even over and above the larger spheres of form; whether such transitions are accessible to observation or whether this cannot be expected from the very outset. All of these questions are and continue to be questions of the natural sciences which do not touch directly upon theology.
Here we are simply presupposing the extreme in evolution as a given or as a hypothetical assumption of the natural scientist, and we are asking only whether something of this sort must be rejected by theology or not. (The emergence of the human being will receive special consideration later.) This, then, is the question: Is a continuous development of the cosmos from its simplest and most original components right up to its present differentiation and complexity, the realm of living being included, acceptable to Christian faith in such a way that it can leave this whole evolution to natural science as a thesis or hypothesis, and then, at most, afterwards include this evolution in a Christian conception of the world?
Our answer is yes. If we at first prescind from the question as to where and to what extent the concept of the fixity of a being, which can be explained only by an act of creation outside of an evolution, is realized in the cosmos; if we put aside the question whether something like this exists beyond the very first and most primordial data of the cosmos, which data modem physics with a certain differentiation simply presupposes (because otherwise the big bang could not be conceived), then this sort of general and continuous development implies only that all respective individual realities in their further development possess in the physical and biological realm the characteristic of the possibility of self-transcendence. Each in its own stage can become something else, can change and become "more" ("higher"), whereby this "more" can of course be quite different, cannot, however, be excluded in the development in favor of simply "being different," regardless of whether such a being different would really contain fewer metaphysical questions than a "being more."
In such a change to more, natural science (if it does not want to abolish itself) will presume on the one hand that at the starting point of such a "development" certain things must necessarily be presupposed without which the result of such a development cannot be achieved. Yet, on the other hand, today's natural science apparently does not wish to understand this development in the sense of a mechanically functioning causality on the basis of which the higher stage could be accounted for in a strictly predictable way (at least in principle). If this were the case, it would actually be questionable whether the starting point of such a development would really have been "less" than its end point, if this starting point would, in fact, have contained in itself the effect in this way as cause. From this it appears that natural science today (when it approaches such borderline questions at all) inclines to the view that in the development more really comes from less, that the old ontological principle is no longer acceptable to it according to which the cause in its reality of being must contain at least as much power of being as its effect in order for it really to be able to be the adequate cause of its effect.
It seems that for faith the actual problem of a continuous and ascending line of development lies here. But faith can still say yes to such a development if the presupposition is granted that, first, divine causality in respect to the finite cosmos is an object of knowledge, and that this knowledge, as knowledge of the transcendental relationship between absolute being and finite being, precedes an application of a general principle of causality, and correspondingly is aprioristic to the knowledge of natural science, second, that with this relationship between absolute being and finite being in the process of becoming there is present (always and everywhere) a determination of self-transcendence coming from absolute being itself, and that this determination is not a particular characteristic which could along with other characteristics be discerned in the finite being with the methods of natural science. The capacity to become more is an ontological determination of every finite being which is necessarily implied in this being, and which includes that more precise relationship of God as continuing creator, which we have indicated above.
So if natural scientists who espouse the idea of a continuous evolution should say that the reality accessible to them with their methods always presents a piece of the cosmos in which more is constantly coming out of less, then an affirmation of this kind pertaining to the empirical area accessible to natural science would not stand in contradiction to the affirmation of faith which declares that this developing cosmos with its stages of constantly recurring self transcendence presupposes the divine reality and its unique relationship to the world.
It is true that here only the most fundamental problem of evolution as a whole is solved in the most abstract and formal way. The individual elements of self-transcendence which must occur in an entire evolution of this kind are of course, at least at first glance, quite different in kind. Especially the complex systems in the biological realm which replicate themselves seem at first to be quite different in kind from complex systems in the purely physical realm. If, however (still prescinding far the time being from humankind), biology today believes that it can reject a vitalism of ancient or modern origin and sees living systems as developing only "from below," then it does not seem opportune to lodge a protest in the name of faith against such a conception of development toward living being, if one accepts as valid only the theological interpretation of evolution as it has just been explained. It is of course quite true that the emergence of animal consciousness in such a development only from below poses a special difficulty which is not removed by pointing to "thinking" computers which we ourselves construct, and which then surprise us by their achievements.
But it cannot be said with certainty either that the origin of animal consciousness cannot be understood in the framework of the general principle of evolution, since this principle asserts an evolution from the lower to the bigger, and theologians do not have to object to this if this development is conceived as standing under that divine influence mentioned before, which does not imply any intervention of God as an individuah factor, such as is required by the old vitalism. That the "leap" of development to animal consciousness goes beyond the possibilities of development in general would have to be proved. One must call to mind that even according to the old scholastic ontology of sensory knowledge the material element is an inner constitutive element of such consciousness and not just an external material basis which the animal consciousness merely "rests upon." Finally, we must call to mind that the old ontology recognized an eductio e potentia materiae for living animal being and obviously saw no ontological problem in this kind of emergence of consciousness from below, even granting that the empirical presuppositions of this conception were not correct.
By way of conclusion, perhaps one might point modestly to the previously mentioned idea of scholastic ontology which says that the forma of each and every being is actually something spiritual, the consciousness of which is impeded only by its being imbedded in matter (in the metaphysical sense). The metaphysician of old would have conceded consciousness to this forma, if it were freed from matter; today's theoretician of evolution could concede the same consciousness to this forma, not indeed if it were freed from matter, but if it is present in a sufficiently elevated organization of matter.
K. Rahner, Theological Investigations, vol. 21 (Darton: Longman&Todd, 1988), pp. 33-41.