Biological Ethics

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Chapter 10. Interactions of Biology and Anthropology, I: Evolution

A. Llano

a) Anthropological implications of biology

The cultural panorama of our time is, to a large extent, characterised by the extension and effectiveness of the scientific explanation of the world. The natural sciences have provided us with a knowledge of the cosmos that has unravelled numerous enigmas and has made it possible to improve man's life in many ways.

It has been insisted above that the scientific knowledge - however extensive and precise it may appear to us - does not exhaust man's cognitive possibilities. We have seen how the level of scientific objectivity - characterised by its universality and rigour - is rooted in a previous cognitive level: the everyday knowledge from which, in one way or another, scientific explanations always start. And we also note that scientific explanations refer to the empirical aspect of reality: they thematise reality as it manifests itself, as it appears in the phenomena of sensible experience (often achieved by sophisticated instruments of observation). This is why positive science is distinguished from Philosophy. Science remains - by its own methodological imperatives - on the phenomenal plane. It does not claim to study reality as it is in itself, but only as it appears to us. For example, Physics does not ask: what is subject?; it limits itself - and this is no small thing - to investigating the laws that govern the movement or action of material bodies. Biology, for its part, does not ask itself about the being or the essence of living organisms; it is concerned, rather, with discovering the laws to which living bodies, vital phenomena, are subject. On the other hand, Philosophy is the knowledge that deals precisely with the being of all these realities. It questions what the subject is in itself, what the essence of life is, what it is to be a human being, etc. That is why we say that the realm of objectivity proper to Philosophy is the ontological level. "Ontological" means that which concerns the intelligibility of the real (on-ontos is a Greek word whose meaning is precisely to be).

We also already know that the attempt to reduce the whole of the human knowledge to that provided by the positive sciences is reductionism. All reductionism consists in taking the part for the whole: in saying "this is nothing more than...". This illegitimate narrowing of the human knowledge is called scientism. In serious and advanced philosophical and scientific circles, positivist scientism is today completely abandoned. But scientism as an ideology, that is, as a conception of the world that pretends to be scientific, but which - in reality - is nothing more than a set of assessments, representations and myths, at the service of unconfessed interests of domination, still remains - and is even spreading.

Overcoming scientistic absolutism opens the way to broadening the horizons of our knowledge. It is, of course, very beneficial for the scientific research itself, which moves away from ideological dogmatisms and becomes aware of its scope and limits. And this overcoming is indispensable to advance towards a philosophical conception of the world and of man that is rigorous and in keeping with our times.

But - assuming that we have overcome scientism - not everything is done: it is a necessary condition, but not sufficient. Because, in distinguishing science from Philosophy, it can happen - and it happens very often - that we separate the two. Distinguishing is not the same as separating. It is necessary to distinguish, but not to separate, but to unite, to seek cultural syntheses that help us to orient ourselves in the world and to have a more certain and complete idea of the whole of reality and, especially, of man.

However different they may be, Science and Philosophy are not - should not be - separated. In fact, between both levels of knowledge there are constant interactions. On the one hand, Science itself makes constant use of philosophical notions: cause, effect, finality, existence, etc. The History of Science sample shows us how many scientific discoveries have philosophical problems or philosophical "intuitions" at their base. Without going back to Galileo or Newton, it is enough to recall Einstein's general theory of relativity or Heisenberg's uncertainty principle. But, on the other hand, the Philosophy cannot do without Science either: it cannot naively pretend to limit itself to the everyday knowledge alone. In fact, the results of science and the scientific research itself pose questions of great interest and problems that the philosopher cannot help but ask himself and try to solve.

These interactions between Science and Philosophy require an interdisciplinary approach . Faced with the current splintering of the landscape of knowledge, it is necessary to move towards new syntheses, in which attempts are made to design broader and more comprehensive conceptual models, integrating scientific discoveries and philosophical interpretations. The obstacles to this endeavour are obvious. Not the least of these is the diversity of languages, which has led to what Professor Polo has called "intellectual babelisation". Philosophers do not understand the "technical" terminology of scientists, and scientists do not quite understand what the "abstractions" of philosophers refer to. But we must know how to turn difficulties into new opportunities for action. To engage in a fruitful interdisciplinary dialogue, both sides need to get clear - "clarify" - what they are doing. And look for points of meeting, which are often to be found in the basic notions that scientists themselves use and which have undoubted philosophical relevance: subject life, life, purpose, truth, language, information, etc. This is already being done in the best universities in the world.

The need for this meeting is especially interesting and urgent in the field of interactions between Biology and Anthropology. On the one hand, biology is perhaps today the most dynamic science, where the most important innovations are taking place. These discoveries raise far-reaching philosophical questions. This is clearly the case in the field of bioethics and the ethics of the research biology. But more fundamentally, the current developments in biology affect the philosophical conception of man, i.e. anthropology. In order to "get an idea" of himself, man today cannot do without biology. And biology itself - in many of its fields - needs a thorough anthropological foundation.

This is the field in which the following considerations will move. Naturally, it is not the intention to deal with all these interactions, nor to solve the difficult theoretical and practical problems that this meeting raises. Rather, the aim is to clarify some basic questions that will facilitate the interdisciplinary dialogue and the scientific work and professor of future biologists.

We will focus our analysis on the points where the most difficult problems are concentrated: evolution and the distinction between human and animal behaviour. The two issues are, in turn, interconnected and not easy to discern. But we will go step by step. First of all, we will deal with a basic topic , which transcends even the object of Anthropology, because it is proper to Metaphysics, that is, the study of reality in itself considered or, as philosophers say, of being as being. It is a question of the relations between the concept of evolution and the concept of creation.

b) Evolution and creation

It seems, from entrance, that evolution and creation are antithetical concepts. Either one is an evolutionist or one is a creationist. Either one believes that the world, life and mankind are the result of an evolutionary process, or one believes that they are the result of God's creative action. It is a question that has long been dividing minds, and which has become highly topical again because of the controversy, especially in the United States, between "evolutionists" and "creationists", even with educational and political repercussions.

Like all great controversies, it has a real basis, it responds to a real problem. But also, as is often the case with this subject of discussions that people are passionate about, there are too many confusions and misunderstandings. Let's say straight away that, properly understood, the notions of creation and evolution are not mutually exclusive. Even if there is a subject of "evolutionism" which is incompatible with the Admissions Office of creation, and a subject of "creationism" which is incompatible with the acceptance of evolution.

Notion of creation

First of all, let us specify the notion of creation. The first thing to say about it is that it is not just a religious idea, the exclusive object of a belief. It is certainly a biblical notion, which Jews, Muslims and Christians accept as a revealed truth. But it is also a metaphysical notion; and metaphysics is a strictly rational science. Therefore - and irrespective of whether or not it is admitted by a religious faith - creation is rationally demonstrable.

This is not the time to attempt to develop the strict demonstration of creation as studied by philosophers. Suffice it to point out that the world has to be created because it is a set of finite, limited realities, which do not have in themselves their raison d'être. Surprising as it may seem, the truth is that the world - the whole set of limited realities - does not have in itself the ultimate explanation of its existence. This is a clear example of the distinction between scientific explanation and philosophical explanation. Each of the cosmic phenomena can perhaps be explained by a scientific law that refers it back to earlier phenomena. But this does not explain the reason for its very reality, the ultimate cause that accounts for its being. Well, this cause final cannot be any finite reality, because none of them is being, but all of them participate in being. If one of these realities were being, instead of having it in a limited way, of participating in it, it would be Being itself, and therefore unlimited and self-sufficient. And none of the things of this world are of that nature. The ultimate Cause of each and every worldly reality must be an absolute Being transcendent to the world, a supreme extra-worldly reality. This metaphysical explanation may seem difficult, but it is, in any case, unavoidable. If we do not accept a transcendent Absolute, we have to suppose that the world itself is absolute, that it gives a reason for itself; and that is tantamount to divinising the world, to turning the finite into the infinite. As Jaspers said, when the Absolute is suppressed, another absolute immediately takes its place. If one wants to avoid Metaphysics, one falls into Myth, more or less enlightened.

But let us not expand on this subject of considerations, which would take us away from our purpose. What interests us now is to specify this metaphysical notion of creation, precisely to clarify that it is not incompatible with the scientific notion of evolution.

Creation is the production of reality "ex nihilo", i.e. out of nothing. But what does "out of nothing" mean here? It cannot mean that "nothingness" is a kind of material from which the world is made. Precisely the opposite is meant: that there is no prior material whatsoever. To create is to produce something out of nothing, i.e. without any previous subject . Creation is not a transformation, but an absolute innovation. The action of creating is not the elaboration of something pre-existing: it is a radical production, a pure performance.

This seems obvious. But some of the consequences that are rigorously deduced from this notion of creation are no longer so obvious. It is important to retain the absolute character of the negation of a pre-existing subject . What was there before creation? Nothing. It seems, then, that there was nothing before and then something. But this is clearly misleading: precisely because there was nothing, one cannot speak of a "before" and an "after" creation. There is no "before creation" and there is no "after creation".

Creation is not a movement: it is an absolute emergence, an original emergence. That is why it is not an "event" that takes place in time. For there to be time there must be movement: a "before" and an "after". And that is what there is not in creation. Properly speaking, creation is not an event. This does not mean that it is not real, but that it is not an event that happened at some point in time and then stopped happening. Creation cannot be understood as a kind of initial "throwing into existence" of things, which would then continue to be, left to their own devices, by a kind of ontological inertia.

No. Creation is something much deeper and more real than a fact. It is the stable status of dependence of creatures on their Creator. It is the metaphysical condition of the created, insofar as it is maintained in being by the original Cause. That is why creation is as real and actual today as it was on the first day of Genesis.

Christians know from the biblical account that there was a beginning of time, that the world came into being, i.e. that it is not eternal. But it would not be contradictory - according to Thomas Aquinas - if the created world were eternal. For, in order for the world to be created, it is not necessary for it to have a beginning, but - so to speak - it is "enough" that it is finite. What interests us in this observation is to insist that creation is not a temporal event, not even if - it is true - the world had a temporal beginning.

As is well known, cosmologists nowadays accept the hypothesis of the "big bang" as a possible initial "event" of the universe. Of course, it seems that our physical world is not eternal, and one can even venture that it is 15 billion years old. The so-called "ultra-creationists" see in these scientific hypotheses an alleged demonstration of the "fact" of creation. Without denying that current cosmology is very coherent with creationist metaphysics, the two planes should not be confused, because - as the astrophysicist Hubert Reeves points out - it is necessary to distinguish between the ontological existence of the universe and the various possible mechanisms of its emergence. Physics is concerned with the how, whereas, as we have seen, metaphysics investigates the radical why. Among other things, it cannot be physically demonstrated that the "Big Bang" was not preceded by a previous cosmic status . uAs Stanley Jaki has said, "Physical Science or scientific Cosmology is utterly powerless to show that any state of material interactions is not reducible to a previous state, however hypothetical. If Science is impotent on this purely scientific question, it is even more so with respect to a much deeper problem, of a very different nature, namely, that a given physical state may owe its existence to a directly creative act, which brought that physical state into being from nothing.1

This observation brings us more directly into our thematic field. For what can be said of cosmological theories applies a fortiori to theories of evolution. Insofar as they are scientific hypotheses, evolutionary theories can neither affirm nor deny anything about the creation of the world, for the fundamental reason that they operate on a different plane goal . The question of evolution concerns the mechanisms of change in the physical world and, more specifically, in biological organisms. It is concerned with the becoming of the world, not with its being. The latter is what Metaphysics is about, which rightly warns us that creation is not an event that can be recorded by means of sensible experience.

Evolution only conflicts with creation when it is formulated from a radical evolutionism, from a universal transformism, which is not a scientific theory but a materialistic ideology. Ideological evolutionism extrapolates the physical postulate that "nothing is created or destroyed, but only transformed", and transfers it to reality as such, i.e. turns it into a crude metaphysical thesis . According to this "scientific conception of the world", there is nothing that is not material and, therefore, the subject has to account for itself and its own transformations, which - one would not know why - lead from the indeterminate to the determinate, from the imperfect to the perfect, according to an alleged law of universal and total progress.

Such a conception excludes, of course, creation and, incidentally, any minimally intelligible philosophical conception, because to place the indeterminate subject as the cause of everything - and even of itself - makes no rational sense whatsoever.

But there is also the opposite, extreme "creationist" position, according to which the created character of the cosmos would exclude all evolution. This position is not metaphysically tenable either. It too confuses the plane of being with that of becoming. And that is why it is thought that every innovation in becoming must be an innovation in being, which would require a special intervention of the creative Cause. Every new stage of the physical universe, every appearance of a new biological species, every real novelty, would have to be explained by appealing to the creative Cause. No account is taken of the fact that the existence and action of a first Cause does not exclude - but rather underlies - the existence and action of the second causes, which are the principles of becoming.

Of course, it appears that things cannot be like that. Created things are not formless pieces of subject which, in order to change, would require constant divine intervention. Creation - let us insist on this - is not an event, it is not a "factum" that had to be repeated. By its very metaphysical nature, creation includes the preservation in being of created things. Philosophers say - rightly - that there is only a distinction of reason between creation and conservation: that is to say, that they are really the same thing, but that when we say "creation" we think rather of the original emergence, while when we say "conservation" we prefer to refer to the stability of what has been created. The conservation of things in being is not - as Descartes thought - a kind of "continued creation": it is simply the creation of things which, also by their very nature, "continue" to exist over time.

For material things to continue to exist in time means to move, to change continuously or, if you prefer, to evolve. An immobile material reality is unthinkable. Therefore, the creation of material things does not exclude the mutation or evolution of these same things; on the contrary, it demands it. Creation must necessarily be evolutionary creation; it is understood that by this we mean something quite different from the creative evolution of the radical transformationalists. To speak of "creative evolution" is to transfer to finite things a self-creative capacity that is rationally inadmissible. On the other hand, "evolutionary creation" is an expression which points to the dynamic character of all created things and, in particular, to the mutability of material realities, due to the work of second causes.

Notion of evolution

Now, it seems that the term "evolution" says more than "movement" or "change". Indeed: evolution is a change in a certain sense. And it also connotes the nuance that this meaning is perfective, that one moves on to something somehow better. Well, if this is taken into account, the compatibility between creation and evolution, which is evoked by the expression "evolutionary creation", must be maintained even more fundamentally. For, as noted above, these realities created by God cannot be meaningless. They must have been created for something and, therefore, be intrinsically endowed with purpose. Although it would take longer to show in detail2, it is easy to understand that every created reality must be finalised, full of meaning, intrinsically directed towards its perfective realisation.

On the plane of becoming, this perfective dynamism - this evolution - is the work of the second causes, that is, of the created realities themselves, which are really capable of operations of their own, by means of which they "realise" themselves. And, in turn, this physical becoming is metaphysically grounded in a creation which not only preserves, but which - proceeding from a supreme Intelligence - also governs and orders. It is the metaphysical idea of providence which - in turn - is demonstrated by the existence of an intelligible order in the world.

Here again there may seem to be a contrast. For the idea of evolution evokes that the process of cosmic becoming is completely autonomous, while the notion of providence evokes the representation of God's occasional or continuous interventions in the things of this world. And again it is observed that the alleged incompatibility only responds to the respective misunderstanding of the two notions. That evolution - if such is the case - scientifically explains the unfolding of the world, is in no way equivalent to the absolute autonomy or complete ontological independence of such processes. In a complementary way, it must be said that providence is a metaphysical notion - an aspect of creative action itself - which does not intertwine with physical causes or interfere in their course, as if it were on the same plane as them. Providence - which is very real - is not a fact, nor is it detectable in empirical experience: it does not enter into "skill" with evolution.

Creation-evolution

Going a step further, we can affirm that - far from being opposed to each other - the metaphysical notion of a provident creation and the physical idea of a cosmological evolution require each other, although - obviously - not in a symmetrical way. On the one hand, if there is a meaningful cosmological and biological evolution, it is necessary to refer - in order to explain it radically, i.e. metaphysically - to a creative Intelligence. And, in turn, this creative Intelligence, although it has created the world freely, must have created a world ordered to an end and, therefore, endowed with meaning.

In the resulting view of things, it cannot be thought that creation comes first and then evolution. For we already know that creation is strictly contemporary with all phases or moments of the evolutionary process. What there really is is a creation - as a stable metaphysical status - of material things that evolve precisely because they have been created with meaning and purpose, and are - therefore - guided by a wise ordering providence. We reject, therefore, two extreme positions, which fail to think adequately about this articulation between creation and evolution.

On the one hand, "ultra-creationism" takes the creative Cause - which is a metaphysical or transcendental Cause - as if it were a physical cause, and pretends to make it intervene in some moments of the evolutionary process. We have already seen the fundamental conceptual defects that this attitude entails. However, a special intervention of the creative cause, which would produce a radical innovation, metaphysically inexplicable by the evolutionary process itself, cannot be excluded as a matter of principle. Whether this is the case with the appearance of life is open to debate. On the one hand, there is no doubt that the emergence of living beings represents an important organisational and functional innovation; but, on the other hand, it does not seem impossible to give a physical explanation of the origin of living organisms from an inert subject , for the fundamental reason that they are strictly intramundane entities. On the other hand, the origin of man requires a different treatment, precisely because the human person is not a totally intramundane reality, but possesses capacities - his intelligence and his freedom - that transcend the subject. Thus, in the case of man we have serious reasons to think that - not only in the appearance of the human species, but in that of each individual man - there must be a special intervention of the creative Cause. But to reach this conclusion we have still a long way to go.

On the other hand, ideological evolutionism, which postulates a transformative and universal autogenesis of the subject: a kind of creative evolution, is not acceptable either. By rejecting all transcendental causation, all conservative and provident creation, this materialistic evolutionism - with which the very concept of evolution is often confused - is forced to choose between reductionism and preformationism in order to account for the emergence of new realities. Reductionism, as we already know, consists in maintaining that the new is nothing more than the initial conditions from which it emerges. In maintaining this, reductionism easily turns into its antithetical position - preformationism - for which there is properly nothing new, because everything was already preformed before. A third position, held more recently3 , is the so-called fulgurationism, for which structural changes - without introducing any new elements - produce "fulgurations", emergences of new things, without any need to resort in any way to the transcendental Cause. As Reinhard Löw4 has shown, these variants of evolutionism fail to account for the new and, paradoxically, lead to a static view of the world.

Teleology of the physical world

The basic conceptual flaw - common, moreover, to both extreme views - is the neglect of the teleological nature of the physical world. According to this finalist conception, the things of the physical world are not exhausted in their mere facticity, in their brute or bare reality, but possess an internal intelligibility: a meaning that manifests itself in the fact that their function is not arbitrary or accidental, but intrinsically oriented towards the attainment of a purpose. This understanding avoids the confusion and confusion of both "ultra-creationism" and reductionist evolutionism. The emergence of the new is only an insurmountable problem for the mechanistic conception of the cosmos, according to which all physical reality is exhausted in the informal subject and in the mechanical laws of its motion. On the other hand, finalism - the teleological worldview - understands physical things not to be mere fragments of subject, but to be endowed with a nature. The nature of physical things is not some mysterious principle hidden in them - something like the "entelechy" of the neo-vitalists - but is their internal formal structure, by which they are capable of functions of their own, directed to their own, i.e. natural, end.

Another thing is whether we know, in each case, what that nature is and precisely what its end is. The trivialisation of finalism - its simplistic presentation as a physical explanation - earned it the rejection of modern mechanicism under the accusation of anthropomorphism, that is, of attributing to physical or biological realities some subject of "intentions" that only man can have. But the teleological conception proposes nothing of the sort. Above all, because it is not a theory to provide concrete physical explanations, but a metaphysical conception of the world and of man, for which all reality is intelligible and endowed with meaning, even if we do not always know concretely what this nature consists of which confers on each thing its own end.

The rejection of teleology by modern mechanicism has already seen its historical exhaustion. Science today is more sensitive to the recognition of the scope and limits of its empirical explanations. And, precisely because of this, it is more open to interaction with a finalist metaphysics that does not claim to provide, in turn, physical explanations, but rather offers a comprehensive framework -a higher horizon of intelligibility- for physical and biological explanations themselves.

The teleological concept of nature allows us to understand the emergence of the new as a update of potentialities ordered to an end. Unlike mechanicism, it does not understand physical reality as an undifferentiated fabric, but as a differentiated order, whose ultimate meaning and purpose is given to it by a transcendent Intelligence. The new is not reduced to the initial conditions, nor is it preformed in them. Nor must the special intervention of the creative Cause be postulated for its emergence. The new has its origin in that principle of operations which is the nature of things: their ontological structure, thanks to which they are capable of innovations congruent with their own way of being. This current approach, which we called fulgurationism, is the one that comes closest to this structural and dynamic approach . But, due to positivist prejudices, it remains in a closed systemic treatment, which also ends up referring the new Structures to their emergence from initial material conditions. On the other hand, teleological naturalism is capable of welcoming those emergent innovations - those fulgurations - that take place in the physical world, precisely because it conceives it as an ordered set of realities capable of authentic innovative actions. Only in this way - from a metaphysical conception of evolutionary and teleological creation - can the meaning of biological evolution be adequately understood.

c) Chance and Necessity in Biological Evolution

In the previous section it has been necessary to make some philosophical incursions, which may not have been easy to follow at some points. But their general result is very useful for our purpose. For one thing, it is to be hoped that they will have contributed to dissolving the misunderstanding that leads to establishing a contrast between creation and evolution. But, above all, they will have opened us to a philosophical conception of the physical world which constitutes a framework Pass to think rigorously about the conceptual presuppositions of the theory of evolution.

There is no doubt - and hardly anyone denies it today - that the theory of evolution proposal by Charles Darwin has played the role of a positive and very active catalyst of the biological research . But this should not make us forget that Darwinian evolutionism was proposed - and, above all, ideologically interpreted - from a mechanistic and materialistic conception of the world, which led many of its followers to a universal transformationism opposed to creationist metaphysics and to the recognition of man's unique place in the cosmos.

The core topic to understand the conceptual flaws of Darwinism lies in its rejection of the notion of nature and, therefore, in its neglect of the teleological nature of physical reality, especially of living organisms. The Darwinian image of the cosmos is ultimately that of a fundamentally undifferentiated material fabric, in which the biological species is not a stable and defined reality. That is why his idea of evolution is basically that of a transformation or mutation of a homogeneous subject . Darwin understands biological evolution as descent, that is, as the successive transformation of one subject of organic individual into another subject of organic individual. However, it is not necessary to understand the origin of living organisms in this way. No one says that a child is "descended" from its parents: rather, we say that it has been generated by them. This is not a simple semantic nuance. The idea of generation carries with it the conviction that living organisms are capable of their own actions, from agreement with their nature. On the other hand, the idea of descent seems to imply that the emergence of new organisms is understood as the mere product of a process of transformation of one material configuration into another, due to external causes. Between the two conceptions average is the distance that separates teleological naturalism from materialistic mechanism.

Let us stress that the undoubtedly strictly scientific merits of Charles Darwin and some of his followers are not in dispute here. Rather, it is a question of the philosophical conception of the world that is at the basis of classical Darwinism. The question is of great cultural significance, because this evolutionary conception subject has permeated very extensively and deeply the contemporary mentality; and not only in the field of Biology, but also in Anthropology, Economics and Sociology (at the end of these reflections, we will briefly deal with current Sociobiology, which constitutes a clear sample of what we want to suggest here).

When Darwin published his book "The Origin of Species" in 1859, he took up the transformist idea that Lamarck had already put forward in his "Philosophy zoology" of 1809. According to Lamarck, living organisms have arisen through a process of evolution, in which some species have been transformed into other species. The mechanism that Lamarck postulates to explain this process is the inheritance of the characters acquired by living beings, as they try to adapt to the environment in which they live. The accumulation of successive changes would eventually lead to a mutation of the species itself. Darwin, for his part, takes up Lamarck's transformist conception, but proposes another mechanism for the training of new species: natural selection in the struggle for life5. Although - unlike Lamarck - Darwin maintains that mutations have an intrinsic origin, he argues that they do not respond to necessary laws, but are random. Strictly speaking, it is an external factor - natural selection in a population limited by an environment - that imposes the survival of the fittest. It was therefore inevitable that Darwinism would give the impression that it proposed a complete worldview, from which all reference letter to the transcendent was excluded. "The reason that Darwin's ideas caused such a stir when they were first announced was that they presented the living world as a world of chance, governed by material forces, rather than as a world governed by a divine plan. They substituted chance for necessity. They transferred evolution from the metaphysical to the natural".6 We already know that evolution and creation are not incompatible. But it is not possible to combine a teleological conception of the cosmos with one that places the main cause of its unfolding in material chance.

Let us understand each other. Finalist metaphysics - for example, Aristotelian metaphysics - does not exclude the presence of chance, but always coordinates it and subordinates it to the natural laws that govern the unfolding of the living subject with a finalist necessity. Nor does Darwinism exclude all necessary law, but even this factor of necessity is understood in a mechanical and ateleological way. Strictly speaking, if finality is suppressed, chance and necessity end up coinciding, since all processes would have a mechanical-material nature. A world dominated by chance would be entirely necessary, in the sense of a mechanical necessity. This convergence between chance and necessity is what - in his own way - Jacques Monod rightly glimpsed in his now famous book.

From its initial formulation, Darwinism was the subject of fierce controversy, involving both ideological motives and scientific explanations7. quotation . But the scientific event that would most seriously challenge the Darwinian approach was the emergence of the modern Genetics by Gregor Mendel. Although Mendel made his experiments known in 1866, they did not become widespread until 1900, when de Vries, Correns and Tschermak put forward genetic theories that coincided with those of Mendel. According to these approaches, genetic traits are stable in nature and are transmitted from one organism to another by mechanisms that are independent of the environment and the soma. Recent molecular biology has also discovered that the mechanisms of heredity are to be found at the level of the genes, in the structure of the DNA molecule. It is only there that the possibilities for hereditary changes are to be found. Increasingly, these genetic mechanisms are being explained by rigorous biochemical laws.

Let us note that, in contrast to Darwinian generalisations, genetic research has the nature of strict scientific explanations. But what we are more interested in now is to stress that the genetic and biochemical approach no longer responds to an undifferentiated conception of the living subject as proposed by materialist mechanicism, but recovers - at the phenomenal level - the idea of form, which, in the last analysis, is perfectly compatible with the notion of nature. What dominates is no longer more or less necessitarian chance. The idea of laws of change reappears, which do not exclude, and even demand, a finalist vision of the cosmos.

As is well known, Darwinism - which continued its course, trying to argue with palaeontological discoveries that would show the existence of continuous series of organisms - was rethought around 1930, incorporating Genetics into the outline of transformational evolutionism, thus giving rise to what was called neo-Darwinism and is today known as the "synthetic theory of evolution"8. What this theory aims to synthesise is precisely the Genetics with the Darwinian idea of natural selection. Neo-Darwinism begins to recognise that not all genetic changes are random and admits that they are usually biologically infeasible and even lethal to the organism. But it argues that the gradual accumulation of random genetic mutations can give rise to new biological configurations that are favourably adapted to a given environment. It is precisely that environment that selects for a particular trait. For that trait to be transmissible, it must be taken up by the population of the corresponding species living in the same ecological environment. It is therefore assumed that such changes occur with sufficient frequency in a given population, so that a reproductive barrier is established with the individuals of the previous population and a new dominant population eventually emerges and takes over.

This is how two qualified neo-Darwinists characterise this synthetic theory: "Evolution takes place by natural selection of the heritable differences that arise randomly in each generation, so that those which give their carriers greater adaptation to the environment will multiply and those which are detrimental will be eliminated. Like Darwinism, the synthetic theory emphasises the opportunistic nature of evolution by natural selection, in that the differences in question are generated by chance and selected in response to environmental requirements, and, on the other hand, postulates the gradual nature of this process"9.

It is not for us to enter now into a detailed discussion of the set of hypotheses that neo-Darwinism aims to synthesise. It is worth remembering, however, that the combination of gradual microevolutionary changes with the macroevolutionary context of a population in a given environment has been seriously questioned by the approaches of palaeontologists Gould and Eldrege, who, since 1972, have disputed the existence of the intermediate stages - the famous "links" - that are still postulated by neo-Darwinism to explain the gradual transition from one species to another. According to these authors, what would have occurred are abrupt and punctual changes followed by long periods of stability10. But the possibility Biochemistry and Genetics of large and rapid evolutionary changes that are, moreover, viable, has yet to be explained. And it is precisely from Molecular Biology that the second and toughest series of objections to neo-Darwinism has come.

The representatives of synthetic theory themselves recognise the strength of these clashes, but downplay the attacks coming from both molecular biology and palaeontology: "These disputes are no more than conflicts of nuance and opinion within a common evolutionary vision. Moreover, we are convinced that by modifying both the traditional position and the competing theories, most of the disagreements can be accommodated within a broader version of synthetic theory. 9 But others are less optimistic or less conciliatory, such as the director of high school Max-Planck, the biologist J. Illies, who goes so far as to say: "Darwinism, despite its many attempts at revival, is long dead. The tragedy of our time is that most biologists do not want to accept it, or have not even noticed it yet"11.

The most scientifically serious - and philosophically relevant - objection to neo-Darwinism comes from molecular biology, for which it is becoming increasingly clear that the appearance of DNA variants is much more a matter of molecular determination than pure chance. As Lima de Faria12 has pointed out, we are now beginning to be in a position to abandon many of the simplifications of neo-Darwinism and to replace them with molecular interpretations. Certainly our knowledge of molecular systems in the cell is still in its infancy. We do not yet know how atomic processes give rise to cellular Structures . Interactions between atomic and cellular levels are still underdeveloped areas of Chemistry, because it is only recently that we have finding realised their importance in connection with biochemical patterning and cell morphogenesis. However, as our knowledge of the laws governing molecular recognition and the laws governing the organisation of DNA, genes and chromosomes grows, the presentation of a "molecular alternative" to neo-Darwinism, which is sample increasingly seen as a simplification of evolutionary processes, becomes more and more viable. This is not to say that natural selection plays no role in evolution, but rather that its importance - as a counterweight to supposedly random alterations - is diminishing as the knowledge of molecular determinations grows. The concepts of mutation and selection take on a new meaning13.

Nor should we abandon neo-Darwinian chance-selection in favour of a new biochemical determinism which, in its own way, would also be reductionist. With Pierre Paul Grassé, it is worth noting that "the intervention of internal factors imposes itself on our reason"14. 14 So that "recourse to a mechanism other than mutational and random is imposed on any system that claims to explain evolution"15. There is no longer as much resistance as there was a few decades ago to recognising that the evolutionary process seems to show certain directive tendencies, as if it responded to a design or a certain plan16, , even if there is still caution - which is, moreover, partly justified - against "vitalist" or "mystical" explanations. The concept of an evolutionary programme, which recognises "critical points" and favoured solutions17 , is increasingly gaining ground.

What is important is that the finalist explanation has once again found its way into science, because "the immanent or essential purpose of living beings is classified among their original properties. It is not discussed, it is proven"18. A researcher as unsuspicious of anti-Darwinism as Ayala, has warned that "some evolutionists have rejected teleological explanations because they have not recognised the different meanings that the term teleology can have (...). They are wrong to claim that all teleological explanations should be excluded from evolutionary theory. These same authors actually use teleological explanations in their work"19. Although Ayala is quick to point out that the presence of natural tendencies in living organisms does not reveal intentional behaviour, nor are they directed towards a certain purpose. And this is frequent among some current biologists. They do not dispute that the living subject manifests teleological properties, "but if the word finality is uttered, they are alarmed. Probably because they do not distinguish de facto or immanent finality from transcendent finality. The biologist has little or nothing to say about the latter; it belongs to the realm of metaphysics"20.

This is the approach from which we started. It is not a question of metaphysical explanations replacing or interfering with strictly biological ones. It is a question of Biology not accepting as if it were a scientific approach the materialistic and mechanistic world view which, as we now see, has constituted an obstacle to authentic scientific progress; and, at the same time, of opening up the respective epistemological planes to interaction with the teleological conception of the world, proper to finalistic metaphysics. Biological science itself continually provides finalistic explanations - for example, it refers to evolutionary changes in order to adapt to the ecological environment - but in it finality is understood more in terms of function than in terms of final cause.

In finalist metaphysics, necessity takes precedence over chance, precisely because the end is understood to be the first of causes. Therefore, the primary meaning of necessity is not that of a mechanical determination, which - on its own - ends up leading to mechanistic necessitarianism, which - in turn - is confused with chance. The primary sense of necessity is formal and teleological: it is given by the nature of each thing, which is its stable principle of formalisation and activity. But since, in addition to the formal and final causes, the existence of material and efficient causes is recognised, the metaphysical necessity of which we are speaking is not absolute, nor does it exclude the presence of a certain margin of chance. Chance occurs precisely when the efficient cause is not directed towards the final cause proper to that thing or organism (which, in the last analysis, happens because the adjustment between the subject and the form is never perfect). Thus, the maintenance of the primacy of necessity does not exclude the recognition of chance, even if it is always a negative and marginal factor.

Neither complete determinism nor complete indeterminism can explain biological evolution. It can only be understood from a limited determinism, which is - simultaneously and inseparably - a limited indeterminism. Only in such a world can there be room for a finalised evolution that is not confused with evolutionary transformationism. For there to be evolution, there must be biological formalities, necessarily determined in their own action; but, at the same time, these same formalities are susceptible to intrinsic mutation, to substantial change, which implies an undoubted factor of indeterminacy, given by the very material nature of organisms. Thus, our world - and, even more clearly, the whole of living organisms - is not a realm of pure formalities that unfold with the implacability of mathematical deduction; but neither is it an undifferentiated fabric of homogeneous materials. It is both a material and a formalised world, whose physical systems and organisms are teleologically oriented with a non-necessitarian necessity, allowing for a margin of indeterminacy.

Such a differentiated and articulated picture of biological reality is perfectly in line with the results of science. It is an open image. And it is also open to the insertion in this world of a being that is not strictly intramundane: man21. But this last question presents its own difficulties and requires a detailed treatment.

Notes

(1) JAKI, S.L. "From Scientific Cosmology to a created Universe". The Irish Astronomical Journal, 15, 260, 1982; ARTIGAS, M. "Las fronteras del evolucionismo". Madrid, 1985.

(2) I refer to the excellent book by R. SPAEMANN and R. LIW, Die Frage Wozu? Munich, 1981. It is superfluous to say that a simplistic conception of finality is not proposed here. In defending a teleological conception of the cosmos, it is not maintained that there is an extrinsic and punctual finality of everything that is or happens. The end of each thing is not a singular object, distinct from itself. It is, rather, its own intrinsic tendency towards the full realisation of its structural project , oriented to some extent towards the realisation of larger projects.

(3) VOLLMER, G. "Evolutionöre Erkenntnistheorie". Stuttgart, 1975; LORENZ, K. "Die Rückseite des Spiegels". Munich, 1973.

(4) LIW, R. "Die Enstehung des Neven in der Natur". In KOSLOWSKI, P., KREUZER, P., and LIW, R. "Evolution und Freiheit". Stuttgart, 1984.

(5) ARTIGAS, M. "Las fronteras del evolucionismo". Madrid, 1985, pp. 76-77.

(6) TAYLOR, G.R. "The great mystery of evolution". Barcelona, 1983, p. 9.

(7) BOWLER, P.J. "The eclipse of Darwinism. Anti-Darwinian evolutionary theories in the decades around 1900". Barcelona, 1985.

(8) The main creators of the synthetic theory are the biologist Julian Huxley, the geneticist Theodosius Dobzhansky, the palaeontologist George Gaylord Simpson and the biogeographer Ernst Mayer.

(9) STEBBINS, G.L. and AYALA, F.J. "The Evolution of Darwinism". research y Ciencia, 108, 42, 1985.

(10) ELDEREDGE, N. and GOULD, S.J. "Punctuated equilibria: an alternative to phyletic gradualism". In SCHOFF, T.J.M. (ed.). "Models in paleobiology". San Francisco, 1972, pp. 82-115.

(11) ILLIES, J. "Schöpfung oder Evolution". Zurich, 1979, p. 33.

(12) LIMA DE FARIA, A. "Molecular Evolution and Organization of the Chromosome" (2nd ed.). Amsterdam, 1986, p. 1083.

(13) LIMA DE FARIA, A. "Emerging principles of physical determinism in evolution". In Molecular Evolution and Organization of the Chromosome (2nd ed.). Amsterdam, 1986, pp. 1067-1085.

(14) GRASSE, P.P. "Evolución de lo viviente". (2nd. revised ed.). Madrid, 1984, pp. 82-83.

(15) GRASSE, P.P. "Evolution of the living". (2nd. revised ed.). Madrid, 1984, p. 340.

(16) TAYLOR, G.R. "The great mystery of evolution". Barcelona, 1983, pp. 12-13.

(17) LOPEZ MORATALLA, N. "Biología molecular del proceso evolutivo". School de Ciencias. University of Navarra. Pamplona, 1987.

(18) GRASSE, P.P. "Evolución de lo viviente". (2nd. revised ed.). Madrid, 1984, pp. 235-236.

(19) DOBZHANSKY, T., AYALA, F.J. STEBBINS, G.L., VALENTINE. "Evolution. Barcelona, 1980, p. 499.

(20) GRASSE, P.P. "Evolution of the Living". (2nd. revised ed.). Madrid, 1984, p. 238; ARTIGAS, M. "Las fronteras del evolucionismo". Madrid, 1985, pp. 118-123.

(21) The proposal, by some cosmologists, of an anthropic principle, according to which man's presence in the cosmos delimits the possibilities of cosmic evolution and supports finalist approaches, is currently being much discussed. BARROW, J.D. and TIPLER, F.J. "The Anthropic Cosmological Principle". Oxford, 1986.