Philosophie et spiritualité - Le virtuel et le réel

Lesson 35 Life and Inertia

Unlike mere things, living beings possess an autonomous principle for change. We find this distinction between things and living things already in Aristotle. According to this philosopher, a living creature exists by nature because it has in itself the principle of its own motion. Aristotle calls this principle psuché, soul, and considers it to be an entelechy or living principle. Thus Aristotle draws a line between the inert level and that of the living. He makes the soul the principle of life. Aristotle reasons from the point of view of a finalist representation of Nature.

However, as we entered the modern age we shifted from a finalist interprÉtation of Nature to a mechanistic vision. Is it possible to maintain the distinction between living and inert things within the framework of our mechanistic science? Symptomatic of modern thinking is to apply the term soul to man only. The progress of biology has clearly shown that many specificities of life should in fact be analysed using material parameters. The question is therefore what status should we confer to this particular ‘object’ that is a living creature and to what extent it can or not be viewed solely as inert matter. The specific problems raised by Biology begin here. Our investigation will therefore start with the question: in what way is the knowledge of living things different from that of inert ones?

* *
*

A. The Living Phenomenon

Let us go back to our first distinctions. One used to speak of the different realms in Nature. This distinction is still relevant from the point of view of scientific nomenclature. The realm of matter refers to Physics, Chemistry, Geology, Astronomy and so on. The realm of life refers to Biology and its subdivisions, Anatomy, Genetics, Histology and so on. The realm of the human refers to the human sciences, among which we find Psychology, Sociology, History, Anthropology. It is tempting to consider life as an intermediary, where what will be built at that stage is being prepared, including the level of human consciousness. Now the question is to know if the division into realms of Nature is merely a convenient picture or if it is an intuition founded in the nature of things.

Are there aspects differentiating the vital phenomenon from the material phenomenon? Let us take a look at a living animal in its natural environment.

1) To the exterior, a living being appears a distinct totality with a certain degree of autonomy. For example, the body of a fox has a sort of inner circuit of extremely complex functions that maintain the equilibrium of an environment at a constant temperature. Homeostasis does not constitute a particular case, but on the contrary the very model of organisation of something alive. The most basic cell has a membrane, forms a whole, a living autonomous unit. All living things constitute a tiny biological world inside the World in general. Even more strange, living organisms are structured like Russian dolls, in totalities fitting into one another. Indeed, what is a cell if not a unity, a small totality? A cell has a centre, the nucleus, a rudimentary digestive and respiratory system, and is delimited from the outside world by a membrane. Its genes contain the totality of information necessary to its development. Beyond the cell is the tissue. Yet the tissue is not just a lot of cells jammed together; it also has the structure of a totality. In other words, what becomes apparent from level of the cell and onwards, and that one also finds in the tissue, is individuation. At the stage above, that of the organ, then at that of the totality of the organism, this value is conserved and maintained. It is impossible to describe a living creature as a pack of disorderly chemical stuff, because, on the contrary, what clearly appears is an order structured as an individual. The first characteristic proper to life is individuation.

2) Living things find their sustenance in their habitat, and it is inside this habitat only that they will find the nourishment adapted to them. The European fox would not survive on the ice fields in the Poles or in the tropical desert. In its habitat it draws what it needs to feed and breathe. Here is a concept fundamental to life: that of need. The gravel on the road has no needs, it neither eats nor breathes. It has no faculty of assimilation. It is possible, however, to interpret these phenomena in chemical terms. We speak of anabolism to refer to the chemical exchange taking place between a living being and its surroundings in the process of absorption. The reverse, the rejection of used substances into the surroundings, is called catabolism. In common they have the original faculty of assimilation, the first distinctive character of living things. From bacterium to man, passing through the plant, living creatures absorb substances and reject them; this is not observed in the mineral realm. When one observes this capacity among minerals, for instance in the case of corals, then one immediately refers to them as living. Living beings stay alive through absorbing or fabricating the food they need to grow and to maintain their vital organs. Food it has ingested thereby becomes the very substance of the feeding organism.

3) Living beings also display the capacity to breathe. In complex reactions of combustions, it transforms the energy of food into energy of use to its own cells. This is also the process of fermentation, closely associated to that of breathing.

4) Living beings are also endowed with a sensitivity to time that is proper to them and that cannot be reduced to the process of entropy at work in matter. They are in a permanent struggle against entropy. They are born, grow, develop and die. These processes typical of life are meaningless in any other context. The duality life/death relates to stages of development of the living individual in which it construes and maintains its own specific type. Added to this we find a unique phenomenon: living beings are able to reproduce. Reproduction constitutes the form of biological continuity of the species via the individual. Globally, inert matter knows only increasing entropy and no reproduction. We may call this development, a unique characteristic that radically distinguishes life from inert matter: only living beings, and not minerals, develop in a manner that is successive, sequential and orderly. Only living beings go through genuine genesis. Only living beings appear able to generate an exact copy of themselves.

5) Living organisms may evolve via complex mechanisms that biology identifies as adaptations and mutations inside an accepted framework which is that of natural selection. Evolution is a word whose primary meaning is found in Biology, as the chief characteristic of living things.

6) Living beings are able to generate their own motion. Unlike material things, they are not just displaced. An elementary bacterium has vibratory flagella, and plants, as shown in the TV program with David Attenborough, The Private Life of Plants, also move towards light or water, albeit so slowly that their motion is best perceived on film.

These six characteristics all refer back to a common property, that of self-reference. This is expressed in:

Self-conservation: first of all, living beings have the ability to stay alive through nutrition, assimilation and converting energy via breathing or fermentation. Self-reference is also expressed in self-reproduction that allows living beings to propagate life via reproduction. Finally self-reference is also expressed by the self-regulation that enables living beings to regulate itself, to overcome imbalances in the external world, to synchronise overall reactions. Living beings are endowed with an often astonishing faculty of adaptation. In order to maintain their individual structure, living things succeed in bending, to a certain extent, to changes in climate, humidity and heat without being destroyed.

These are the principal structural characters that allow us to differentiate living phenomena from merely material ones. These characteristics are so specific that Biology has been made into a field separate from Physics.

B. Biological reductionnism.

However, progress in Biology has mostly consisted in relating these properties to chemical phenomena, in such a way that explaining life has often meant showing how a process of life occurs, and this in terms of chemical conversions and molecular structures. Biological reductionism is the doctrine stating that biological phenomena are not really that specific and that they can be explained by reference to physical and chemical phenomena. Already Claude Bernard declared: “life is just a word due to ignorance and when we say of a phenomenon that it is “vital”, this is equivalent to saying that it is a phenomenon of which we ignore the cause or the condition” (Claude Bernard, An Introduction to the Study of Experimental Medicine). In other words, were we in possession of a solid mechanistic explanation, this would immediately destroy the specificity we confer to living phenomena. Similarly, to invoke a “vital principle”, a “soul” in order to account for a living phenomenon would be to introduce an irrational element in our explanation and thereby confess our ignorance of what is really occurring. That is, the “real” is physical and chemical. Reductionism gets its strength from some fundamental arguments:

That living stuff contains no other chemical elements than those we find in inert stuff: nitrogen, carbon, hydrogen, oxygen etc… The chemical bricks that compose living creatures are not very different from any matter. Life could arise only from matter, of which it is merely a modification.

One has succeeded with the artificial synthesis of many substances formerly believed to be generated by living creatures only. Grafts and transplants of organs tend to show that an organism is similar to a machine, the parts of which can be removed and replaced with spares.

Let us go back to the three aspects of self-reference mentioned above and examine how they occur. Reductionism replies to questions beginning with “how”.

a) Self- conservation is an important challenge. How do living beings withstand attacks from outside? They must behave a little like a transformer of energy permanently connected to a source, the sun. They must be capable to use this energy economically. By analogy with Mechanics, in the same way as a car requires constant maintenance, “a living cell must maintain its structure against the irreversible degradation due to time. There are mechanics that deal with cars, and the cell must be its own mechanic”. Putting things back in order is costly in energy. The more organised or orderly a system is (like a cell) the more energy it requires to maintain its organisation against the natural tendency to disorder. How can this phenomenon be accounted for? The inert world is subject to increasing entropy. Life does not function like inert matter, since it is in direct contradiction with the second law of thermodynamics, which stipulates that any material system will tend to disorder. In order to fight disorder, living beings must constantly absorb new energy which they take from their food. They must feed in order to maintain their structure. Energy emitted by the sun is captured by plants in photosynthesis, after which it is eaten by higher organisms. An economical circuit of energy is established between plants, sun and animals, that makes the permanence of life possible. These are the exchanges of carbon dioxide, glucose, water and oxygen which this system enables.

b) Self-replication is also explained by chemical mechanisms; the cell can be shown to be very much a molecular factory. Not only does this factory look after its own maintenance, but it can also build its own machines. Self-replication corresponds to two specific functions of the cell, copy the bricks of life and permanently manage metabolism. This is the task of structuring proteins and of enzymes. Research in Genetics has shown that the bricks of life are structuring proteins. The blueprint of the house is written inside a protein, the DNA. It has been shown that DNA codes for all the information relating to an organism.

Self-regulation means that, when managing cells, the living being must not only propagate and sustain itself, but also regulate itself. How is it able to decide which enzyme to make? Who makes the decision? In order to understand these mechanisms, one has to look at the field of cybernetics, that is the study of robots. A cybernetic machine is a machine endowed with a certain degree of self-regulation. Reductionism wants to show that the ability to self-regulate is a chemical phenomenon and not just a biological one. When the central heating in my house starts as result of a thermostat, then there is self-regulation. In the body of a living being homeostasis is a similar procedure. An analogous circuit exists between DNA and RNA. Messenger RNA serves as the intermediary in the transmission of instructions from the DNA to manufacture enzymes which, working in a manner one might compare to one along a production line, generate the molecules necessary for the survival of the cell, the metabolites. These can either block the line fabricating them or act in such a way as to continue the production. This way the cell is permanently adapting production to its needs.

Thus Genetics show the biochemical mechanisms that explain living phenomena by relating them to material (physical) phenomena. It has become impossible to defend an anti-reductionist point of view, one at odds with the official doctrine. One can no longer in Biology propose and defend the existence of something like a “vital principle” or a “soul” in order to explain the difference between life and inert matter. Between matter and life there is continuity, transitions. In Thermodynamics modern Physics has been able to show that the emergence of self-organisation occurs even inside material systems. If one evaporates salty water one can observe the spontaneous formation of crystals, and this is the formation of order. These are properties analogous to those we find in life. Prigogine, a physicist working with Thermodynamics, has shown that self-organisation is one of the results of the dissipation of the energy of an open system into its surroundings. These he calls “dissipating structures”.

Reductionism thinks that it can show the mechanisms underlying the self-refering structures of living beings. Yet is this really the problem? No one has said that finalism excludes mechanisms. Quite the contrary! The self-referral complexity of life demands that this self-reference takes places by means of certain mechanisms. But this does not imply that life itself is mechanical. Life utilises mechanisms, but the self-referral intelligence that uses the mechanisms must necessarily transcend them. We must be careful here: it is not because we use a mechanistic paradigm of explanation that this one is reality itself. We must not mix up representation, that is the system we use to explain reality, with reality itself.

C. The complexity of Life and Evolution.

Yet is it really worth our trouble to revisit the conflict between reductionism and anti-reductionism? Why go looking for a radical duality between life and inertia?

One way of overcoming this duality is to consider the fecundity of the action of Time. A material system self-organises far from equilibrium and can behave like a clockwork, develop spatial structures such that one may conclude that in fact disorder knows how to get orderly. It would seem then that had Nature not repeatedly turned the conditions of life on Earth upside down, had climate, geological accidents, solar irruption and ecological combinations not changed in wholly unpredictable ways, then there would probably never have appeared new structures, making it possible for new living species to emerge through dissipating energy. According to Prigogine, what is at stake in this debate is an archaic concept of time founded on a belief in determinism. On the contrary, if genuine time includes the unpredictable and the new, then nothing prohibits that it generate order out of disorder. Nature spontaneously self-organises, because self-organisation is inherent in the nature of Nature, and nothing can prevent it from structuring itself into ever more complex levels. It is unnecessary to invoke some special, non-physical force in order to explain life, such as scholastic entelechies. But one cannot either brutally oppose on the one hand a material universe ruled by entropy and on the other hand life ruled by negentropy.

In these conditions, even the biosphere of the Earth could very well constitute a gigantic self-regulating living entity, such as the one proposed by James Lovelock’s Gaïa Hypothesis. The new logic of self-organisation derived from Thermodynamics does not exclude it. Better even: from this angle life appears to have spontaneously emerged from matter with, from the start, intelligence, imagination and considerable creative power. We will discuss this later on.

But what we now perceive more clearly is that the matter of the universe is organised into a long chain of increasing complexity. This chain begins with the properties of the quantum field, continues with elementary particles, atoms, molecules, cells, individual organisms and finally extends to the complex groups that are ecological habitats and human societies. Each level of complexity brings the building blocks that will be used to construct the next level. This is what Teilhard de Chardin understood already in 1916 and tries to show in The Human Phenomenon.

By definition a system is all the more complex that it possesses a greater number of elements depending on one another. In this sense, the brain, composed of billions of cells, is more complex than bacteria. However the number and variety of connections is even more important than the number of elements. In a complex system the Whole is more than the sum of the parts. Biological complexity is not just organisation in space, but organisation in Time. This time is all the duration of evolution. For example when comparing the skull bones of apes, ancient and contemporary, with those of the Australopithecus, of the homo erectus, the homo habilis, the Neanderthal man and ourselves, one unfolds a process spanning 60 millions years and with an apparently implacable logic: the law of complexity-consciousness. Were it demonstrated that the course of time follows this direction, then one would have to amend the merely “chaotic” vision of the theory of evolution. There may well be a logic unfolding within the halo of randomness, a logic that feeds on chance, yet obstinately progresses towards a higher and higher complexity-consciousness.

* *
*

One thing is to recognise the specificity of life, another to explain it with reference to inertia using the mechanistic paradigm, and yet to look for levels of complexity inside reality. Reductionism is a doctrine with an ideological bias. It is not science. Nevertheless it is true that it is implicit inside a very literal interprÉtation of the mechanistic paradigm. The distinction of levels of complexity in reality pertains to metaphysics. One example of this is found in an essay by Teilhard de Chardin. influenced by Christian presuppositions. Another is the prodigious exposition by Sri Aurobindo in his major work, Divine Life.

The question is to decide which concepts are authorised within the framework of Biology, given its objective paradigm. There is more in the living than in inert matter. In the living Nature has made a leap in complexity while including the prior realm.

* *
*

dialogue : questions and answers