Jacques Maritain Center: Thomistic Institute

Nature, Life and Teleology

Vittorio Possenti
(University of Venice)

One observation forces itself upon us at the outset. It is just as hard to think about the problem of life today as it was a hundred or a thousand years ago. If we observe the state of the sciences, we are led to the conviction that an important issue still remains open: to develop a philosophy of life and the organism which is adequate to the level of biological discoveries. Our most urgent need in the dialogue between science, philosophy and theology does not arise, as it has happened for centuries, from physics and cosmology but from the life sciences, notably biology and genetics. This is a necessity on which thinkers of different schools, such as H. Jonas and J. Polkinghorne (1), are agreed. Physics is no longer the guiding science, or the sole guiding science: its place has been taken by biology and it is high time that philosophy and theology turned to address the issues it raises, without entrusting the realm of nature and life solely to the sciences. While there is still a rich crop of studies about Big Bang theory and scientific cosmology in general, little has been written on philosophical biology, where the presence of the theologians has been exiguous. One may wonder why this should be so: perhaps because Big Bang theory seems allusively to evoke the truth of the creation, though a more careful consideration of this scientific theory, rather controversial and highly 'speculative', shows that it has nothing to do with the theme of creation, as it deals only with the cosmic becoming: as such it is unable to formulate statements on what transcends becoming and then on creation, understood as the total position in being of all things. But one may also conjecture that this insufficient interest in biology stems from the difficult problem of teleology and, more generally, from the reductionist attitude frequently displayed by scientists, when they pass beyond their own field of research and formulate hypotheses and theories with universal implications, prompted by an unbridled enthusiasm which has proved ill-advised on other occasions in the past.

Perhaps we can reconstruct a parallel between the post-Newtonians' enthusiasm for mechanicalism and the passion of biologists today for biology and genetics. The former, intoxicated by the spectacular conquests of Newtonian physics, claimed that man was no more than a machine, no doubt highly complex and delicate, but a machine all the same. A similar intellectual euphoria now seems to have infected certain biologists, over-eager to think of man as merely a biological machine equipped for survival.

The difficulties of thinking about life are aggravated by the profound shift in perspective brought about by modern scientific cosmology, which has since merely become more acute. This phenomenon could be described as a "regression of life due to the enlargement of the universe". Once nearly everything was life; today nearly nothing is: in our universe, enlarged out of all proportion, almost everything is mass, energy, inanimate force. We have passed from the ancient panvitalism to the current situation in which life is rare and improbable in the universe, when precisely it is not fundamentally reduced to non-life, to mechanically and chemically ordered matter (pan-mechanicalism). One might suppose that this attitude is connected with the immense enlargement of the cosmos due to the doctrine of an expanding universe, unknown to the ancients: as the dimensions of the cosmos have grown, the biosphere has shrunk proportionately, and it represents a much small percentage of the cosmos. Though it has some foundation, this position is not the whole truth, since it is also the fruit of the modern tendency to reduce the organic to the inorganic. All this creates a dialectical situation in biology: on the one hand it is a marginal science, since the biosphere forms no more than a tiny party of the universe; on the other it is central, because it deals with what counts most: life, including human life.

However, the cultural change from ancient to modern times is clear. The problem for the ancients was life and organism, and for so their works contain numerous manifestations of animism and hylozoism. (By animism I mean the idea that attributes a soul to all things, including those that we consider inert; and by hylozoism the assumption that the principle of life is originally intrinsic to matter). This evokes the obvious reference to Plato, who saw the whole cosmos as a living being endowed with perfection and beauty (cf. Timaeus, 30 b-d). So the ancients saw matter not as res extensa but as res vitalis, so to speak. Though they possessed very few and shaky notions of biology, their culture was biological, vitalistic, organicist.

If this was the problem of the ancients, that of the moderns has been the problem of the spirit and with it the res extensa-res cogitans dualism. The hegemony of this dualism - completely unsuited to understanding the phenomenon of life, which cannot be reduced either to extension or to thought - entailed either the expulsion of the problem of life from research or else the project to reduce life to a mechanical element, starting from the assumption that the fundamental phenomenon is not action but the movement of that which is inanimate, studied in mechanics. Parallel with these developments, the concept of nature as the inner principle of movement and life was inevitably rejected. "Nature" as res extensa was abandoned to science, while philosophy from Descartes to Husserl has confined itself to the realm of spirit/thought. The authentic concept of nature is not understood either by the naturalists-nominalists, who reduce it to a classificatory idea, nor by the spiritualists, who see it as something deleterious, an obstacle or a limit to the spontaneity and freedom of the self.

The greater awareness that now exists about the nature of life should finally lead us to reject this dualism, which causes an almost endless series of misunderstandings. If one still wants to speak of "dualism", it remains possible in relation to the "body-soul" nexus, which has little connection with the concept of res extensa-res cogitans, unless we presuppose the Cartesian mechanicalism, namely the idea of the body-automaton, which entails a complete rejection if the concept of life: the automaton is in fact an inanimate mechanism. The Cartesian mechanicalism, contrary to all evidence and all common sense, has been abandoned even in reductionist theories of life, as is shown by various contemporary positions, in which the vital is reduced to physico-chemical and thermodynamic reactions, never to mere extension. (2)

Nature and life

A reasonably well informed observer will perceive that the question of nature is extremely delicate and gives rise to numerous controversies. This is due to its marked semantic multiplicity and ubiquity, which tend to foster ambiguity rather than clarity. The difficulties inherent in the conception of nature are hardly new, since over three centuries ago Pascal, in his scintillating style, had already framed a weighty objection to it in just two lines: "J'ai grand peur que cette nature ne soit elle même qu'une première coutume" (3). Not far from Pascal's position is that expressed by the contemporary historicist school, which sees the concept of nature as always historical, cultural, and hence variable, relative to a period and its specific culture. We all know the important moral implications of these positions in the debates over the environment, sexuality, family, and bioethics: what is natural and what not? we often ask ourselves. Is the concept of nature morally relevant? Are some things unnatural and contrary to nature?

Pascal's observation implies a criticism. If nature is a habit or a custom, then like all habits it will be liable to change and so cannot provide a solid basis for normative judgments. The changes implied by Pascal's idea of nature will be both diachronic and synchronic, that is affected by differences in both time and place, and vary according to the different cultures present on the planet. This concept, which various phases of Greek thought, including stoicism, presented as making for universality, a bridge between different cultures, and which gave rise to the influential and enduring concept of kata physin, is now understood as a relative and cultural concept, hence incapable of constituting a universal and transcultural ambit.

There remains the question whether Pascal's objection helps us to think about the problems inherent in a philosophy of nature and the organism, to which we shall now turn. A denial, which I feel is inevitable, depends on the perspective in which Pascal is placed: that of a moral point of view, not the perspective of life and of philosophy of nature. This suggests we should look in a different direction for an idea of nature more suitable for the phenomenon of life. Here the trail has been blazed by Aristotle, notably in the Physics and Metaphysics, and continued by various authors, among whom Thomas Aquinas in his comments on these works as well as in other places.

As a preliminary step in understanding Aquinas's treatment of the concept of nature, it is worth introducing the way he defines and comments on it. Pietro da Bergamo's Tabula aurea lists 50 positions or items containing the term "nature", and 25 containing "natural", without counting the fact that the Tabula almost always lists numerous references to Aquinas's works for each single position. The considerable frequency of occurrences of the term 'nature' (fewer, however, than others such as Anima, Deus, Gratia, Christus, Fides - though this should hardly be surprising given that Aquinas is a theologian) provides extrinsic but significant testimony to its importance.

Taking my cue from some of these citations, I should like to enter the epistemological ambit of natural philosophy, a term not free from ambiguities yet significant, charged with echoes and a persistent fascination, since even Monod in his essay L'Hasard et la Necessité (Chance and necessity) uses it in his subtitle ("Essay on the natural philosophy of contemporary biology"), despite the risks it entails, of which the author is lucidly aware. The immense development of the modern sciences has not extinguished - in fact it has at times made even more acute - the desire for a philosophical understanding of the cosmos and life, though in the face of their relentless advance both philosophy and theology have preferred to occupy themselves with history and left nature to the sciences. Hence the almost chronic weakness of the philosophy of nature, the risks of an accentuated concordism between faith/theology and science, and the turning of theology towards hermeneutics.

I have gathered three sentences on nature in Aquinas' works:

  1. Naturalia sunt quorum principium est natura; natura autem est principium motus et quietis in eo in quo est (In Phys, L. I, lectio 1, n. 3)

  2. - Natura nihil aliud est quam principium motus et quietis in eo in quo est primo et per se et non secundum accidens (L. II, lectio 1, n. 145; cfr. Fisica, l. II, 192 b 20s)

  3. - Nomen naturae primo impositum est ad significandam generationem viventium, quae dicitur nativitas. Et quia huiusmodi generatio est a principio intrinseco, extensum est hoc nomen ad significandum principium intrinsecum cuiuscumque motus (S. Th., I, q. 29, a. 1, ad 4m) (4).

From these definitions it appears that nature, an intrinsically analogous concept, far from being a hypostatized entity or an extrinsic principle, exists with and in natural beings (5). Its central character is of being a principle of automovement and change from within: its inwardness or immanence is expressed by the term in quo est, which marks the difference between natural and artificial, in the sense that artificial objects receive change from without. This action which emanates from within comes out more deeply as higher and more perfect is the nature from which it proceeds. For a correct understanding of the Latin wording, we have to remember that motus, being understood in its broad sense - as local movement, growth, diminution, alteration - signifies change or mutation. As nature establishes the existence of an inside, it proves to be a principle of inwardness. In Aquinas's works there are numerous passages in which he follows Aristotle by distinguishing between transitive action and immanent action: the latter being peculiar only to living beings (6). The concept of immanent action, whose source and term lie within the active subject, is the immediate explanation of the idea of nature denoted by "in quo est": where there is nature, there is immanent action. Both aspects of selfmovement and change from within point towards the phenomenon of life, on which we shall return.

Since the concept of nature defined in this way refers to nasci, to nativitas, and hence to the generation of living things, we are directed towards the reality of life and led to explore the concept of life. The link connecting the concepts of nature and life is attested by the fact that self-movement is peculiar to life: "Movere se ipsum pertinet ad rationem vitae, et est proprie animatorum (7). And again: " Primo autem dicimus animal vivere, quando incipit ex se motum habere….Vitae nomen sumitur ex quodam exterius apparenti circa rem, quod est movere seipsum". The continuation of this period includes in movere se ipsum also agere ad operationem (8). Life consists in the fact that a certain substance moves itself in such a way that its action proceed from itself and remain within itself, that it be beginning and end of its action. The concept of nature as the inward principle of movement and of quiet in a being, and that of life as manifesting itself as self-movement, are so closely interwoven as to form almost a single concept. In the wake of these observations one can understand the distance that separates the concepts of nature as employed by the scientist and the philosopher: for the former, Nature (with a capital N) is almost always synonymous with the cosmos, the universe, where life is very rare, while the philosopher sees "nature" as the principle within every living thing. In this sense physical, inanimate Nature, which represents the great bulk of the cosmos, does not possess "nature".

The subject endowed with life appears as an individual being which has its own center within itself, in opposition or diversity to the rest of the world, and possessing an essential boundary between inner and outer (9). This situation can be explained by resorting to the idea of form, as Jonas does, emphasizing its partial independence from matter. In the metabolism as a dynamic function of exchange with the environment, the organism remains identical to itself, not in terms of matter, which alters through this exchange, but in terms of its form, which persists. In reflecting on life we are led to discover the concept of form in two versions: an inanimate version where form results from the aggregation of particles of matter; and a vitalistic version, where form is the cause of the unity of the living being.

"Natura est principium motus et quietis in eo in quo est". Confronted with this definition of nature that refers to change and rest, to concepts that we are accustomed to understand in rigorously mechanical terms, we are strongly tempted to suppose that it is superseded and of little relevance to the bioethical and philosophical problems that so often arise in the field of scientific-biological and genetic discoveries.

But it is wise to suspend judgment until we can see more clearly and grasp what lies unsaid, what the formula does not say openly to our ears, which have been accustomed for centuries to a different music. To this end we need to undertake a further exploration, actually a fairly extensive one, since after three centuries of Newtonian physics and the like we tend to believe, on the whole, that motion with its laws is always induced from without, not from within. One of the major postulates of Newtonian physics, whose privileged locus lies in its application to inanimate objects and which is suited to mechanicalism, is that every movement is induced from without, never from within: a force is exerted between bodies (gravity); one body strikes another and sets it in motion. That there can exist an inner principle of movement is extraneous to Newtonian physics: it was not conceived for the phenomenon of life, but focused solely upon the inanimate. Newtonian mechanics is an essay on the outside world, in the sense that inwardness is unknown and the actions and reactions it deals with concern only the outside. If, on the contrary, the definition advanced by Aristotle and Aquinas refers to nature as the principle of the movement and the quiet that reside in the subject itself, for the sake of symmetry we could say that their natural philosophy is an essay also on the inside world, on immanence, on that which is intrinsic and lies within the subject. It might be objected that after Newton much progress has been made by the sciences and biology, which have enlarged the picture from mechanics to take in the exchange of heat, chemical and molecular reactions, electromagnetism, etc. Nothing could be truer, and yet the phenomenon of life can only be understood by resorting to an inner principle of self-construction.

Two problems

Now, in the light of the ideas of nature and life I have introduced, I shall try to meditate on two problems: A) the question of teleology; B) whether in Aquinas there is some principle or criterion that provides a basis for a philosophy of the evolution of life. This will be a preliminary survey of topics whose extreme complexity hardly needs to be stressed.

A) The question of teleology

When one begins to reflect on teleology/finality, he immediately comes up against a well-known objection: teleology is out of court because modern science refuses to recognize it and rejects it as useless. Science has, in fact, been constructed on a lengthy battle against Aristotelianism under the aegis of the exclusion of all final causes. However their exclusion is an a priori proscription of modern science, in the sense that it is not the outcome of reasoning and verification, but it is a postulate imposed right from the start: "As for final causes it is evident that their rejection [by modern science] was a methodological principle that guided the inquiry and not the conclusion of results obtained by inquiry." (10) On the problem of teleology, the Cartesian dualism accepted as a gentle metaphysic in the service of science long proved useful for the needs of scientists and theists, since it enabled both to manage the vast zone of the res extensa mathematically, omitting from it a zone for the spirit, for consciousness, where teleology alone was valid.

The solution of excluding final causes from nature (which was understood as pure res extensa) and conveniently marginalizing them in the minimum area of the res cogitans, while exploiting to the utmost the advantages of the thought-matter dualism, functioned for a certain period. But when this dualism failed and was transformed in the nineteenth century into materialistic monism, in which both organism and thought were reduced to matter alone, it then offered no advantages at all: if man and his consciousness, in which finality is undeniable, are a part of nature, how can one seriously maintain that final causes ought to be excluded from nature? In this regard materialistic monism is playing on two contradictory tables, because it makes man, in whom it recognizes the category of finality, a part of nature, to which it denies all teleology.

Since final causes are causes, finality turns out to be an integral part of the great question of causality, which has remained substantially unresolved in the course of modern philosophy after Hume and Kant, in the sense that it appears as a form that places phenomena in a temporal sequence, instead of as an event with many facets but real, one which produces something in being. To understand the universal presence and nature of causality, we need to abandon the categories of the intellect (Kant) and to descend into concrete bodily and biological life; and from there to begin again to understand the many ways of real causation, which cannot be reduced to efficient causes alone and still less to mechanical causes.

The idea of finality is not related to any form of change whatsoever, but to those changes directed to an end, and in a more meaningful and strong way to those movements which proceed from less perfect to more perfect and which can be grasped by intellect analysis. In development of an organism teleology represents exactly such a movement from the less to the more. Now it happens that if we have recourse to laws and methods of mathematical type in the movement analysis, the very idea of a more and of a less perfect loses meaning as mathematics does not know that idea. In principle sciences which heavily use mathematical method in the realm of life, necessarily neglect teleology right from the start.

The problem of final causes can be embodied in a number of questions that are periodically reproposed: do purposes exist even where they are not projected by man? Is the concept of purpose valid and present only where there is a thinking consciousness that raises and choices them? For the supporters of final causes the solution lies in showing that finality is not just a concept projected by man onto things, nor a concept that can be employed only in the sphere of consciousness, but that final causes exist in the whole sphere of living things, not only those endowed with subjectivity and will. On the contrary, the modern exclusion of purpose concerns both ontogenesis and phylogenesis. On the basis of this exclusion, ontogenesis is understood as the necessary effect of efficient causes that stem from the determinations contained in the seed; and phylogenesis is the result of random mutations and natural selection. Once final causes are excluded from ontogenesis and phylogenesis, it seems that they remain applicable only to conscious subjects, or rather to that part of their actions that are dependent on consciousness. So there would be finality in walking, since the subject decides where he is heading for, but not in breathing or digesting, which are involuntary functions. However the exclusion of final causes from ontogenesis is not self-evident (think of the teleology immanent in the embryo), so that today rejection of final causes seems much commoner within the ambit of evolution (phylogenesis).

The purpose in renewing discussion about final causes entails taking up the subject again from its most difficult side, that of the difficulties we meet in dealing with the question of purpose in artificial objects, in inanimate objects, and in the life of organisms not endowed with consciousness. We are, in fact, disposed to concede by direct introspective experience that subjects endowed with consciousness form representations of their purposes and act on the basis of those purposes. There is nothing more natural, it seems, than to raise a wall between the two classes and decide that while conscious subjects conceive the idea of a purpose, inanimate objects, artificial objects, and living beings lacking consciousness, are devoid of any purpose, and that applying the idea of a purpose to them is no more than an anthropomorphic projection. However, the question is by no means so simple.

Artificial objects (a term I intend to use in a broad sense) are those made by man and can be subdivided into inanimate objects, like a knife, and animate objects made up of people like a parliament. In both cases, that is in man-made objects, the purpose - attributed always by man himself - is the cause of their production, of their coming into existence; but this happens in different ways. In inanimate things the aim is external, it does not reside in the things themselves but in the mind of their designer. The knife is made to cut and this teleology stems form the mind of the craftsman, it is not immanent in the knife, which is devoid of any purposes of its own and possesses those that the craftsman assigns to it, so that here there is a divide separating purpose and object. By contrast, in "animate objects", such as social institutions, the purpose is immanent. If we take the example of a parliament, its existence is inseparable from its purpose: if the purpose ceases, the parliament as such is dissolved. An external observer who examined its activities without knowing anything about its purpose could only conclude that it is a meaningless gathering of people: he sees individuals who will acquire meaning only if their purpose is known and they are not intelligible without it. Moreover the individuals who make up the parliament share the same purpose as the institution, which is not external, as in the previous example. Both in the case of inanimate objects and that of animate objects, the idea of an artificial object cannot be conceived without that of its purpose, which is precisely the cause of its coming into existence.

A further problem is posed by organisms not endowed with consciousness or by those parts of the human body whose functioning is involuntary, such as the digestive apparatus in the example given above, and in both cases it seems difficult to deny the existence of an immanent teleology intrinsic to the very operation of the organism or of the single organ. It should not be forgotten that finality is not only external, i.e. of the whole that is directed towards some end, but it is also and firstly within the organism, even where there exist purposes without intentions. The final causes have to be retrieved within every organism endowed with life, however small and insignificant it is. Undoubtedly one has to avoid any kind of anthropomorphism in considering the purpose, as would happen if we held that an arrow shot by an archer at a target was a sufficient proof of final causes. In reality it is an incorrect and anthropomorphic example of final causes. The notion of final causes, far from being first established on the level of conscious beings and then extrapolated out of them, should be ascertained from the primordial viewpoint of the being qua agent, within the nexus between the agent and its action, by which the risk of anthropomorphism is avoided.

To sum up this point: in Aquinas we meet with a voluntary finality through which the agent moves freely or by choice towards a known end; and a "physical" finality by which the agent moves either towards an end known instinctively (as in the case of animals) or else in executive way towards an end not known in any way (as in plants) (11). The ontological and gnoseological thematization of these aspects of the question takes the form of what it was later agreed to call the "principle of finality", of which I shall provide two formulations: a) potentia dicitur ad actum (potency refers to act); b) omne agens agit propter finem (every agent acts in view of an end/purpose) (12).

In the first case the final cause is understood as an intrinsic ordering of the potency to act, and its question is related to the primordial nexus between potency and act that is valid in ever subject liable to change. Finality as immanent ordering of potency to act is present in all beings subject to change. Consequently this formulation of principle of finality does not possess transcendental range, as it does not apply to God where potency is absent. In the second formulation of the principle, there appears the decisive term "agent", which possesses far more general implications and range than the term "efficient cause". Reflection on the principle of finality involves a reflection on the concept of agent and action (immanent, transitive, with or without consciousness), and indirectly on that of nature as a principle of becoming. Unlike the first, the second formulation of principle of finality possesses transcendental range and it applies also to the divine action.

To introduce the theme of final causes we have to relaunch a philosophy of action (in an ontological sense even before a moral sense). If we turn our attention to the efficient cause, we come up against the disadvantage of placing ourselves on the side of transitive action alone, forgetting immanent action, where nothing is produced but one's own being is perfected. Newtonian physics, like Monod's biology, in which only efficient causes are considered, are tributaries of an impoverished idea of action and of agent, in the sense that the only action considered is that which works from the outside, so that immanent action and the inner finality of the organism are cancelled (13).

A philosophy of action and nature can be found in H. Jonas, especially in two well-known works, Das Prinzip Verantwortung (Il principio responsabilità); Organismus und Freiheit (Organismo e libertà), which seek to explore multiple forms of action, without postulating a priori the non-existence of a final cause. Jonas's careful analysis, which it is not possible to reconstruct here, reaches an important conclusion: "It therefore makes sense (and is not just a metaphor borrowed from our subjectivity) to speak of the immanent purpose, even though wholly unconscious and involuntary, of digestion and the digestive tract of a living body, and to speak of life as the purpose in itself of this body... The 'aim', apart from all consciousness, whether animal or human, has in this way been extended to the physical world as its originating principle" (14). And in the second of the works cited above: "There is no organism without teleology, there is no teleology without inwardness, and besides life can be known only by life." (15).

This means - to repeat another statement by Jonas - that God is never a pure mathematician. One notes the similarity between Jonas's ideas and a philosophy of nature of a vital and teleological stamp to which we are referring, a similarity that stems from the theme of appetitus (appetition), which is found throughout living nature, to which Jonas devotes an adequate space. Appetition constitutes an important form of action (16). In substance the concept of nature signifies not just an operation from within but also an operation in conformity with a purpose: nature is auto-activity towards ends, and even a non-deliberate or non-intentional purpose is real. Think of instinct, which does not know and yet functions towards an end. The mechanistic dualism of the res extensa, by which Descartes equated animals with machines and automata, stripped them of all inwardness. They possess no inside, they include no nature as an inner principle of movement. Cartesianism renders the phenomenon of life unintelligible and transforms the concept of soul, which is altered from the principle and form of life into a locus of pure subjectivity (res cogitans).

Teleology thus seems to appear or disappear depending on whether one adopts a philosophical or scientific approach. The latter adopts a completely disontologized method, which may be useful on its plane, that of purely scientific explanations, and which generally entails an a priori exclusion of all purpose. However, it is essential not to confuse methodological utility of disregarding finality in sciences and ontological judgment directed to the real being, as Jonas suggests (17). This position is similar to Maritan's: both observe that natural science fails to tell us everything about nature and that a different (ontological) approach is called for, one that seeks to integrate final causes into the explanation of life. On the plane of scientific method, several scholars consider that the idea of understanding life scientifically (i.e. through physics and chemistry) means assimilating it to that which is not life; it means equating organic with inorganic, setting aside teleology: this is the mechanistic version of the philosophy of nature. For those who adopt a philosophical method, life is understood as a peculiar and original phenomenon; they avoid undue reductionism and hence remain open to the possibility of teleology. It is not rash to add that since scientific method fails to consider either the intrinsic potency-act nexus or the concept of action/agent but only efficient causes, science seems unequipped to recognize teleology.

Attempts to cancel final causes, and move towards a "new mechanicalism" applied to life, include that accomplished by J. Monod in L'Hasard et la Necessité (Il caso e la necessità). Monod seeks to explain embryogenesis and ontogenesis only by means of physical and chemical laws, embracing an explicitly reductionist project: "Living beings are chemical machines" (18). The organism, though understood as a machine sui generis, which is constructed by itself - i.e. that is not constructed like ordinary machines through the action of external forces and instruments acting on particles of matter (cf. p.48) - is assimilated to a machine. The reduction of the living organism to a machine cancels nature as a principle of activity from within and distances the idea that there exist multiple degrees of immanent activity. Another grave limitation of this position is that it marginalizes the ambit of appetition, of the "inclination towards", which cannot be explained in mechanistic terms or reduced to an efficient cause. Monod's perspectives are a consequence of the markedly reductionist premises he adopts, among them, the exclusion of all final causes. According to the author the fundamental postulate of scientific method is that nature is objective and not projective (19), and so the only purpose we can speak of is that within a human subject and his conscious activity.

Monod recognizes three characteristics of living things: teleonomy, autonomous morphogenesis, and reproductive invariability. The third element is easy to understand as it means the unchanging transmission of species' characteristics; teleonomy hints at the fact that all living things are endowed with a project; autonomous morphogenesis alludes to the self-construction: living things construct themselves by themselves. However his systematic refusal to resort to final causes leads firstly to an epistemological contradiction between the postulate of objectivity of nature and teleonomy (the former excludes the teleology which the latter invokes) and secondly to "reducing" teleonomy, which becomes a secondary property derived from invariability, the only one that is valid as a primitive property (the fundamental biological invariability is the DNA: the gene is the unvarying bearer of hereditary characters). This is defended as the only position consistent with the postulate of the objectivity of science, which denies final causes: the exclusion of teleology is not, however, a result but an a priori prohibition raised by modern science (20).

If the philosophical biology advanced by Monod does away with the idea of nature as the inner principle of movement, it places a heavy burden on the sphere of liberty, which meets with its first attestation and its first (though minimal) condition in the idea of nature as it is presented here: it is nature that, not reduced to receive forces and messages from without but acting as self-movement and self-construction, conveys the first stirrings of freedom. By contrast, in a universe where everything is determined from outside, it is impossible for freedom to exist, since one condition for its existence is, in fact, immanent action, capable of development starting from within.

B) Evolution

In hinting at the difficult problem of evolution, we will mention two problems: a) the relationship between creation and becoming; b) the possibility that the hylemorphic doctrines of Aquinas be able of justifying evolution of life better than other recent theories such as that of Monod. We will be concerned solely with evolution of life, putting aside theories on the evolution of universe, presently in fashion in relation with the subtle Big Bang theory. However it is wise not to undervalue the mutual support that this theory and that on evolution offer, though physical becoming of universe and life evolution stay as two very different processes.

a) Creation and becoming. Through the principle creatio non est mutatio, of very high importance in Thomas Aquinas and in Christian theology, it is clarified the impassable difference between creation understood as the total and absolute position of all things in being (creatio ex nihilo) and change or transformation (mutatio), which supposes existence of that which is/will be subject to becoming and transformation. Now, the realm of becoming and cosmic evolution entirely belongs to the mutatio and is wholly separate and without influence on creatio. As creating does not mean to be cause of the becoming, creation accounts for the existence of things, not for their becoming, which sets a different field of research (21). The very activity of divine causality operates differently in creation and becoming. In the former He is not only prime cause but unique and total cause of all being; while in the latter He operates as prime but not unique cause, because we have to consider also secondary causes endowed with ability of action and causality.

Philosophy and theology will address themselves to the doctrine of creation which according to Aquinas is accessible to the knowledge of reason (22). On the contrary the realm of change, becoming, cosmic evolution is doubly accessible: to the consideration of philosophy through the analysis of becoming (dialectics of act and potency) and of hylemorphic doctrine; and to the analysis of different sciences. The field of philosophy of nature is exactly the realm of mutatio of every degree and order. Consequently there is no possibility of proving or disproving scientifically the philosophical and theological doctrine of creation, as science is concerned only with laws of universal becoming. The idea that scientific fallibilist theories such as that of Big Bang can confirm the truth of creation rests on impossible harmonies.

I add that the Big Bang hypothesis stimulates the mind, since it seems to contradict a generally accepted rational postulate, that more cannot come from less. On the basis of this postulate, how can we suppose that in an initial, extremely concentrated, mechanical, energy-rich and thermodynamic nucleus be pre-contained the whole future development of the cosmos in its almost infinite forms, and life in all its endless richness? How can we exclude that there exists another guiding, transforming, elevating causality? Jonas similarly observes that in the Big Bang model the effect is greatly superior to the cause: "In this new sense of 'origins' we observe a total reversal of the most ancient idea of the superiority of the creative cause to its effect. It was always supposed that the cause must have contained not just more force but also greater perfection that the effect. The producer must have grater 'reality' than that which it produces: it has to be superior even in its formal essence, so as to explain the degree of form enjoyed by the things deduced from it" (23). The model of genetic deduction introduced by the moderns inverts this order and considers the less as the origin of the more.

b) Aquinas and evolution of life. Evolution can mean simply change, but it also means oriented change, "change towards". At once the question arises whether it moves towards more complex and perfect forms of life, so that the assumption id verius quod posterius (that which comes after, this is truer) is valid. This way of understanding evolution does not exhibit, at first sight, a character of unreality or unreasonableness. Hence a second question: if evolution is directed towards a growing complexity, what ontological metaphysics presents itself as best suited to offer a foundation and an explanation of this event?

In evolution the principal problem to consider is not so much ontogenesis as phylogenesis, the passage or transformation from species to species. Anyone who desires to take the subject of evolution seriously is unlikely to conceive of it in any way except as an event that produces a change of being, i.e. a substantial transformation from which emerges a new living being that previously did not exist. This approach is different from that in which evolution is presented as a simple unfolding of what was given originally, in which - as Bergson seems to maintain - no substantial transformations take place but the unfolding of a single flow of life and élan vital which never ends and leads we know not where.

Our aim here must necessarily be somewhat limited: to show that Aquinas's hylemorphic and "vitalistic" ontology includes certain intriguing doctrines which can be used in formulating an evolutionary conception. We shall take as our starting point a passage in the Summa Contra Gentiles which deals with the ascending perfection of forms (and substances) in the process of generation and the related substantial transformations, and so opens a path towards a philosophy of evolution of life:

"And so, the more posterior and more perfect an act is, the more fundamentally is the inclination of matter directed toward it. Hence, in regard to the last and most perfect act that matter can attain, the inclination of matter whereby it desires form must be inclined as toward the ultimate end of generation. Now, among the acts pertaining to forms, certain gradations are found. Thus, prime matter is in potency, first of all, to the form of an element. When it is existing under the form of an element it is in potency to the form of a mixed body; that is why the elements are matter for the mixed body. Considered under the form of a mixed body, it is in potency to a vegetative soul, for this sort of soul is the act of a body. In turn, the vegetative soul is in potency to a sensitive soul, and a sensitive one to an intellectual one. This the process of generation shows: at the start of generation there is the embryo living with plant life, later with animal life, and finally with human life. After this last type of form, no later and more noble form is found in the order of generable and corruptible things. Therefore, the ultimate end of the whole process of generation is the human soul, and the matter tends toward it as toward an ultimate form. So, elements exist for the sake of mixed bodies; these latter exist for the sake of living bodies, among which plants exist for animals, and animals for men. Therefore, man is the end of the whole order of generation" (24).

Shortly before this we find another noteworthy passage: "Prime matter tends to perfection in acquiring in act a form that before it possessed only potentially, though it ceases in this way from having in act that it previously possesses: for in this way matter receives all the forms to which it is in potency, so that its potentiality is brought to act by stages, since it is unable to do so simultaneously" (my stress).

Aquinas' doctrine transmitted in the above quotations, and in general hylemorphic doctrine about matter-form relationship, should be understood in its scope. It is a philosophical doctrine which can support and clarify those scientific theories according to which evolution of life is really passed from vegetable to animal stage and then to a human one. Supposing that sufficient empirical evidences are available on the 'fact' of life evolution, then Aquinas position can be used in order to account on how life evolution be occurred.

His position seems to suggest that the evolution of life has terminated in man. J. Maritain understood it in these terms, in a study in which he advanced the hypothesis that evolution is essentially completed by the appearance of the human species (25). Evolution has been ascendant and went from the vegetable to the animal, then passed to the world of the spirit with the advent of man, and here it seems to have stopped. This presents the fascinating hypothesis that while the physical evolution of the cosmos may continue endlessly, that of life has already completed its fundamental stages and from now on little is to be expected of it. However the idea that ascending evolution has ended with man does not imply that every other level of evolution is over; it is not unlikely that evolution of vegetable and animal species can go on. Naturally there remain all the great questions about how life appeared and then how the spirit developed from it, but in a certain sense they appear to be questions about the past.

Now, if we pay attention to some positions of the new epistemology of physics, as for instance that developed by I. Prigogine -, very attentive to the phenomenon of irreversibility, to the so-called 'arrow of physical time' -, are not we obliged to recognize that Aquinas' treatment seems too much lineal and simple, too little open to surprise and novelty? Follower of the position according to which we find out in Nature bifurcations, instabilities, surprises, Prigogine explains his view as follows: "Everywhere we direct our observation, we find evolutions, diversifications, instabilities…The vision of nature has been subjected to a radical change in respect of the multiple, of the temporal, of the complex" (26). Anyway, as the arrow of time means that cosmos has an history, this perspective is analogous and perhaps homogeneous with Aquinas' idea of a becoming of life due to really new compositions of prime matter and an unlimited multiplicity of forms. Should Aquinas have conceived this idea in a frame of fixity, this outcome is not essential to the argumentation, which can be placed in a dynamic horizon: we hardly conceive how many beings can proceed from always new compositions of matter and form, in a position open to ontological pluralism. This also implies that for philosophy of being evolution of life is natural, while for Monod it is to some extent pathological, a deviation from normal status. The respective philosophies of evolution differ as are different the conceptions of becoming of being and that of invariance or stability of being: the first one according to Aquinas; the latter according to Monod.

In fact, his framework is quite different: evolution is not explained as a process within becoming, in the nexus between matter and gradually changing forms, but as an event due to chance and to defects in the mechanism of invariance. In opposition to Aquinas, where we find a natural idea of the evolution of life, he holds that "evolution is not a property of living beings, since its roots lie in the imperfections themselves of the conservative mechanism which, by contrast, represents their only privilege" (27). Monod is a supporter of stability, of the "prodigious stability of certain species that have succeeded in reproducing without appreciable variations for hundreds of millions of years" (p. 94). Here evolution emerges paradoxically from a stable context and emerges not through an intrinsic disposition of the "prime matter" to change of form, but on the basis of chance (28).

When related to chance, evolution is not "natural", it is an exception. Necessity, invariance, stability are the rule, to such an extent that teleonomy is related to invariance: "The essential teleonomic project consists in the transmission, from one generation to another, of the content of invariancy characteristic of the species". When writing these words, Monod, though fiercely hostile to final causes, is forced to admit them: the purpose is the transmission of invariance (29). Another decisive step is taken by observing that in living things "spontaneous structuring must be considered as a mechanism" (p. 26). Removing "nature" as an activity and as self-construction from within, omitting the link between agent, action and purpose, reducing autonomous morphogenesis to a mechanism, to a stable structure supported by invariance (as happens in the case of lifeless crystalline structures), creates the necessary and sufficient premises to reduce life to non-life.

The variation that gives rise to evolution is random and hence unpredictable. Random mutations are seized on by invariance and transformed into necessity: "Chance alone gives rise to all change, all creation in the biosphere" (30). Chance and necessity also signify contingency plus necessity, a mixture difficult to handle. Evolution thus emerges as almost a pathology of the normal and the previously existing, or one might say that Monod's has a conception of evolution as an exception (31). These theories, in which man emerges by chance from the random working of evolutionary mechanisms, help to eliminate from science and culture the idea of natural theology, of a universe created by a wise mind, in which man be the image of God.

The important objections which weaken Monod's position should not lead us to refuse it totally. In my opinion it should be necessary to correlate two lines of argumentation which do not contradict each other: the line of ontology and philosophy of nature, which through hylemorphic doctrine can account of accidental and substantial transformations and of the causes required for this; and the line of empirical sciences which, according to Monod, tries to explain evolution as a combination of chance and necessity. That a series of unrelated causes can produce a random mutation in an organism and that this can be incorporated through invariance, well all this can be explained with a different frame of concepts which points to the idea of substantial transformations and of causes required for this output. It is wise to coordinate Monod with Aquinas, but giving direction to the latter. Stripped of its absoluteness, Monod's position on chance and evolution can be partially recuperated, as an element capable of giving rise to different versions of the matter-form relationship.


The definition of the concepts of nature, of life and of finality that emerges from the positions we have described appears to be of a type that is not a priori but ontological-real. They start from the following methodological approach: to study and understand life means devoting oneself to studying and understanding living beings: in them form is not imposed from the outside, as it happens in objects produced by technology, but the living process is the activity itself of the form. By contrast, for some time now, matter devoid of life has become the knowable par excellence, that in relation to which we seek to explain life. For materialistic monism the most natural and original state of things is not to be alive. It follows that it is the existence of life in a mechanical universe that requires an explanation, and the explanation has to be advanced in terms of that which is devoid of life. By contrast Aquinas's ontological and epistemological paradigm as embodied in his philosophy of nature and of life offers a different way of understanding this subject (32). While it can accept within narrow limits the evolution model based upon chance and necessity, it is similar to that based on organism and freedom (Jonas). The latter does justice to the commonsense insight that sees life as an open, self-organizing evolutionary phenomenon.


(1) The latter observes: "Down to the present the debate [between science and theology] has been too much under the control of scientists trained as physicists ... We urgently need the participation of more biologists, more experts in the human sciences, and naturally more theologians", Credere in Dio nell'età della scienza, Raffaello Cortina, Milan 2000, p. 93.

(2) The hope that the Cartesian dualism may be superseded does not imply the end of all forms of dualism. The discovery of the two spheres of matter and spirit which took the place of primitive panvitalism and hylozoism - an achievement of Greek thought - introduced a new theoretical situation which had once again to be reckoned with. Some form of dualism is a better solution than panvitalism alone or panmaterialism alone.

(3) n. 93, ed. Brunschvicg.

(4) In Metaphysics (1014 b 16ss) Aristotle reviews the various meanings of nature (cf. also the comment of Aquinas on n. 808). In Aquinas cf. also on the various meanings of nature: S. Th., III, q. 2, a. 1; and Contra Gentiles, L. IV, c. 35, n. 3: "The term nature was originally used to indicate the generation of creatures that are born". Cf. also the study by G. Cottier "Le concept de nature chez saint Thomas", offprint from: Collana 'Dialogo di filosofia', n. 10, Herder-Università Lateranense, Rome 1993, pp. 37-64.

Note in passing - without giving the topic all the emphasis it merits - that on the basis of the concept of nature and life in Aquinas, it is life that is natural, not death. This seems to contrast with the contemporary spiritual climate, in which death is so strongly connected to life that it is death that is natural rather than life. Once men asked themselves about the meaning of death; now they ask the same question about life.

(5) If life and biological-organic life are not equivalent concepts this means that the concept of life is in itself analogous: there exist different embodiments or levels of life, and a single term is use to denote very different forms of life. The problem is made more acute by the poverty of terms available in Italian and English: we say life to indicate animal life, human life, and ultra-human life: and in man to denote bodily life, psychic life, and spiritual life. In Greek, by contrast, there are three terms that indicate the broad differences in the phenomenon of life: zoé, bios, psyché.

Zoé indicates the life manifested in all organic beings; in a certain way it is the principle of life, whose contrary is not death but non-life, since those that die are single living organic entities, but not the principle of life itself. It is significant that the Greek of the N.T. uses the term zoé also to indicate eternal life (cf. Jn 12, 25). Bios alludes to the modes or conditions of life: if zoé is the life by which we live (qua vivimus), bios is the life we live (quam vivimus). We know that the different modes or conditions of life, such as the political, the theoretical or the contemplative life, are rendered into Greek using bios accompanied by the relevant adjective. Psyche is the vital breath, the soul, and hence also life (also in this regard the reference to Jn 12, 25 may be relevant: "He that loves his life loses it, he that hates his life...", where life is psyché). It remains doubtful whether "biology" is the most suitable term to indicate the object of this science; perhaps it has paid the price of the meaning previously acquired by the term "zoology". All things considered, if I may express a well-grounded preference, the neologism zoelogy seems more appropriate than biology. However the common usage has its force and it is convenient to follow it.

(6) "Actio immanens est tantum viventium", De potentia, q. 10, a. 1.

(7) In Phys, L. VIII, l. 7, n. 1026.

(8) S. Th., I, q. 18, a. 1 and a. 2. Cf. also Contra Gentiles, l. I, c. 97.

(9) Cf. H. Jonas, Organismo e libertà, edited by P. Becchi, Einaudi, Turin 1999, p. 110 e 113.

(10) Organismo e libertà, cit., p. 47.

(11) "Proprium est naturae rationalis ut tendat in finem quasi se agens vel ducens ad finem : naturae vero irrationalis, quasi ab alio acta vel ducta, sive in finem apprehensum, sicut bruta animalia, sive in finem non apprehensum, sicut ea quae omnino cognitione carent ", S. Th., I II, q. 1, a. 2.

(12) The formula 'omne agens agit propter finem" can be found, for instance, in S. Th., I, q. 44, a. 4; I II, q. 1, a. 2; q. 6, a. 1; q. 9, a. 1; q. 12, a. 1.

In the Critique of Judgment Kant recovers finality, but stops short at the antithesis by which an end is either real, but then is present in the consciousness as a principle of intentional action, or is attributed to the technique of nature, but then is only a subjective rule of the reflecting judgment. For Aristotle even a non-intentional end can exist and have an objective reality. On the concept of intrinsic finality cf. Physics, l. II, c. 8.

Hegel insists upon finality with particular vigor and revalues Aristotle's position, especially in the Encyclopaedia: cf. nn. 55, 204, 360. "The definition Aristotle gives of life already contains inner finality; and it is thus infinitely higher than the concept of modern teleology, which has before it only the finite finality, external finality" (n. 204).

(13) Monod invokes both external forces, that have produced and forged artificial objects, and internal forces or "internal morphogenetic interactions" (cf. p. 22) that operate in the living being. By this term, on the one hand he approaches the idea of nature, since the organization of the living thing is not imposed on it from outside but from inside, on the other he interprets internal forces as efficient causes and this fails to escape from mechanicalism. We know, moreover, that for Monod the scientific method consists in a systematic refusal to consider final causes, understood as a project (cf. p. 29). It is symptomatic that Monod understands finality only as project, not as an inner nexus between agent and end.

(14) Il principio responsabilità, Einaudi, Turin 1993, p. 94.

(15) Organismo e libertà, cit., p. 127.

(16) On appetition/appetitus cf. S. Th. I, q. 6, a. 1, ad 2m; q. 59, a. 1; q. 80, a. 1; III, q. 29, a. 1.

(17) Il principio responsabilità, cit., p. 88.

(18) Il caso e la necessità, Mondadori, Milan 1970, p. 47.

(19) Ivi, p. 17.

(20) Cf. ivi, p. 32.

(21) In a thorough study by William Carroll we read: "To use Big Bang cosmology either to affirm creation or to deny it is an example of misunderstandings of both cosmology and creation… The Big bang described by modern cosmologists is a change; it is not creation. The natural sciences cannot themselves provide an ultimate account for the existence of all things. It does not follow, however, that reason remains silent about the origin of the universe. Reason embraces more than the categories of the natural sciences", "Thomas Aquinas and Big Bang Cosmology", Sapientia, n. 53, 1998, p. 81 e p. 93.

(22) Cf. De potentia, q. 3, a. 5.

(23) H. Jonas, Organismo e libertà, cit., p. 54.

(24) Summa Contra Gentiles, l. III, c. 22, trans. by V.J. Bourke, University of Notre Dame Press: Notre Dame 1975, pp. 86-87.

(25) Cf. "Vers une idée thomiste de l'évolution" in Approches sans entraves, Fayard, Paris 1973, pp. 105-162.

(26) I. Prigogine, I. Stengers, La nuova alleanza, Einaudi, Turin 1981, p. 274.

(27) Il caso e la necessità, cit., p.98.

(28) "The only mechanism through which the structure and performance of a protein could be modified and these modifications transmitted, even in part, to its offspring is that which derives form an alteration of the instructions contained in a segment of its DNA sequence." (ivi, p. 94).

(29) Ivi, p. 25.

(30) Ivi, p. 95s.

(31) In Monod's scheme invariance is both affirmed to provide a place for stability and also denied to find a place for mutations, which are the contrary of invariance. Invariance seems to be a sort of revolving door that now blocks mutation and now accepts and fixes it. It is denied to find a place for mutation and then straight after affirmed to find a place for the transmission of the mutation. If we wanted to translate Monod's scientific language into the philosophical language of hylemorphism, we would have to say that the formal cause in Monod is invariance, i.e. the DNA that controls the invariance of the species.

(32) Interesting points concerning the theme of life are found in the volume AA. VV., La vita, edited by M. Sanchez Sorondo, PUL-Mursia, Rome 1998. Also note the essay "La realtà ontologica dell'evoluzione: dall'universo ordinato alla terra da costruire", by L. Galleni, in AA. VV., Prismi di verità, edited by M. Malaguti, Città Nuova, Rome 1997, pp. 141-166. This study insists on the fact that "no reflection of God and hence of God the creator can forego the description of nature and hence of the creation that comes to us from science" (p. 141). Three different theories of evolution are also presented: gene-centered evolution, close to Darwin and Monod (random genic mutations and ordering through natural selection); organism-centered evolution, or evolution of self-organization, in which the appearance of ordered structures in living things is due to phenomena of self-organization; biosphere-centered evolution, which assumes as its scientific object the whole biosphere and the relationships of living things to one another and to the non-living; and which seeks to identify a preferential direction in evolution towards forms of greater complexity (this is the case of Teilhard de Chardin and the assumption of the evolutionary movement towards the noosphere).