Pier Luigi Luisi

1. I would like to begin with a couple of observations about the meaning of the term "purpose." First of all I would suggest that the very notion of "purpose" is meaningless apart from the context of a conscious thinker. The thinker observes a working system and attributes to it a "purpose", a relation between the performed work and the aim of this work. The biologist observes the motion of an amoeba towards food, and attributes a purpose to this swimming. The amoeba has nothing to do with this attribution, the amoeba just swims driven by forces in a concentration gradient, and does not know it. The "purpose" is a mere mental construction of the scientist observer, it depends on his/her intelligence, on his race, religion, scientific beliefs. This implies that the notion of purpose is not objective, but it is contextual, changing in time and is probably different in different societies and traditions and point of time.

2. Also, apart from that, the notion of purpose is contextual in another sense: it depends on the level of inquiry we choose to work with. Looking at a car, we can ask the purpose of the single components—the motor, the wheels, the battery...and we find a local purpose each time. We also recognize that all these components conjure to make up the whole structure—the car. Likewise, the single organs in a man have each one distinct purpose, and they together have the purpose of making the man. Thus, looking at the things of nature—rain and trees, sun light and oxygen and water and earth and seasons, each thing has a purpose, and they all have the purpose of keeping nature alive. Actually, one could make the point that the purpose of science is to elucidate the purpose of the various things of nature, to discover their functional relationship; and that we can measure our ignorance by the extent to which we do not understand the purpose of things existing in nature. At any rate, at this lower, mechanistic levels, the notion of purpose is easier. More difficult is the question of the purpose of the existence of the whole structure per se. Actually, one can ask whether by operating at this higher level (what is the purpose of life, of nature, of the planets and of the cosmos...) we are still within the realm of science.

3. I assume, that in this meeting we are dealing with this higher level of inquiry. Also, I understand (and I am happy with that) that we should deal with this question without invoking divine creation. Then, for the sake of simplicity, I can rephrase the question of the meeting for myself in the following way: what is the view of modern science on the question of the purpose of nature, assuming that there is no creator God, and accepting that the notion of purpose is a mental construct of the scientist himself, depending namely on the particular bias and beliefs of present modern science?

If there is no creator, the complex structures around us are the product of self-organization. For example biology books describe that life originated from inanimate matter through a series of spontaneous processes. First bacteria originated, and from those, multicellular organisms arose in the course of evolution, and from those fish and amphibians and then mammals including men. So, all popped out by itself and reached the present state of complexity.

And the question is then, whether self-organization is endowed with some kind of goal. Or better: the question is whether the conscious observer, the scientist, is capable or willing to impute a goal to nature he sees around himself.

1. For simplicity, one can reduce the term "nature" to the term "life", as nature without life would have no sense for us. Does science see a purpose in life? In order to make this question more focused and simpler, let us consider a simple bacterium—forgetting man for the moment. What is the "purpose" of a bacterium? Or better: what does science say about the purpose of life at the level of a single bacterium—based on the definition of life that science can give at this moment?

Bacterial life, science says, is essentially self-maintenance within a boundary of its own making (I utilize here the framework of autopoiesis, with some simplifications). In other words, the compounds which in a cell are consumed or transformed, are re-generated by the cell itself, due to its internal processes—so that the cell remains always the same, despite a complex network of thousands of reactions. The main function of a living cell is thus to defend its own identity—to remain itself in the face of the many transformations which take place inside its boundary.

The purpose of a life is thus to maintain its self-identity. This view, which comes out from the analysis of simple bacteria as well as multicellular organisms, can be extended to all living species and even to societies of ants and other animals. It can be extended to the planet Earth, when the Earth is seen as a single living planet, as the Gaia proponents suggest.

We would have then reached this conclusion: that the observer scientist who looks at nature and asks the question: is there a purpose in the living nature? Is obliged to answer, in force of his/her own philosophical bias which dominate science today, that nature's purpose is self-maintenance. And nothing else.

1. The notion of evolution needs here a qualification. One may in fact argue that living species evolve: the observer sees evolution towards complexity as a main factor in living organisms, which moves living beings in the course of millennia towards higher forms, up to man, and therefore up to the spiritual development. This might seem like a higher purpose for the living, for nature in general. Love, intelligence, consciousness, the higher attributes of man, can be considered, by this conscious observer, as a purpose for nature—nature evolves, and this is the purpose. This is fine: we said that the definition of purpose depends on the bias of the observers. There are conscious observers who, in force of their own philosophical or ethical beliefs, think that evolution and the reaching of spiritual levels is a purpose in nature.

However, another observer, who is more consistent with the view that "there are only molecules and their interactions", can offer an alternative view: that evolution is not a goal, but simply a result of survival strategy, namely a strategy for life maintenance. A population of bacteria evolves (changes by mutation processes) because it has to, under the pressure which comes from the environmental changes. Changes are random, do not aim per se at survival, they have no purpose. Only if, out of these chance mutations, some are such which correspond to a new species with a higher reproduction rate under novel conditions, the species will survive in a new form—otherwise it will disappear. Thus, according to this view, evolution is not a movement towards the fulfillment of a higher purpose—it is merely survival strategy. Life forms tend to self-maintain, and only under necessity do change, and change the least amount which is possible. Whether this view is antispiritualistic, is per se a quite different issue. Some scientist colleagues of mine are ready to make the point that human behaviour and consciousness can be seen as emergent properties of matter—but this is another issue which we cannot address here.

We have then reached the conclusion that the existence or not of a purpose in nature depends on the philosophical bias of the conscious thinker—that there are a plurality of answers, even within the scientific community, depending upon the conceptual framework. Of course, this reifies the initial statement, that the notion of purpose is not an objective, scientific concept, but a contextual one. In both the extreme cases we have outlined here the different notions of purpose may serve as a guideline and philosophical framework for further research.


Pier Luigi Luisi

I would like to present here the view of modern biological science about the notion of meaning in Nature. This view can be inferred from biology and chemistry text books, as well as from the often unspoken philosophical principles which underlie the view of the scientists in the natural sciences in this particular period in time.

For me, the most powerful philosophical milestone of modern biological science concerning the notion of life and meaning is the tacit understanding that life on this planet derives from non-life; that there has been namely a continuum (called generally molecular evolution) going from the dead matter to the evolution of man – without divine intervention. This seems to me a quite generally accepted statement in the modern bio-sciences – as very few scientists in the field of biology, molecular biology and chemistry would object to that. But this view brings about a series of important conceptual consequences – for example that our world – including man and human behavior – is made up only by molecules and their dynamic patterns – as there was nothing else during molecular and biological evolution to stand upon; And this is a statement that arises immediate protests and cries from our friends philosophers and humanists. To cite Plato and give Greek citations in the context of "purpose" is fine – but this does not change the bare reality of our textbooks in biology and chemistry all around the world. This is indeed a battlefield: does the molecular view implies that there is no place for spirit and soul in our scientific conception of the world?

I would like to present this view of modern biology at large in the form of a science fiction tale, partly because of my professional love for writing children books, but also because telling a tale allows me to speak in a third person, which in turn will allow me to bring forth statements which represent the scientific establishment – and not necessarily my own. So this is the story.


As you know, there are intelligent beings in the Alpha Centauri who are commonly referred to as Green Men. One day, the Director of the Board of Extra-galactic Enterprises sent a young explorer to give a look at the Earth as a part of his examinations for becoming an explorer. In particular, he should clarify whether there was a purpose in the frenetic activity observed on that planet. The young explorer started with a question:

—What do you understand by "purpose", Sir?

—Purpose entails the notion of a plan, of a directionality of development. Is there an intelligence in the plan of Nature on Earth, is it pointing towards a determined goal? This is what I mean by purpose.

—Something is not yet clear to me, Sir. This purpose, this directionality of intent, must be assessed by someone, by an observer – for example by me or by the men on Earth. It is then the product of the consciousness of an observer, and probably does not make any sense to talk of "purpose" of nature as an objective reality. For example, Sir, I can say that the sun has the purpose of warming up the planet Earth and permit life on it. But in reality, Sir, the sun has no purpose, it is simply there, and what I call purpose is just an imposition of my mind. It seems to me, Sir, that the notion of purpose is a pure mental construction of the observer – and thus depends on his/her cultural background, which in turn implies that the notion of purpose is not objective, but contextual, changing in time and according to society and tradition.

—Okay, my young man, let us accept this. So, go and look whether on Earth there is a purpose in the plans of Nature – even though this purpose may be considered as a mental construct of yours. Just go!


The young green explorer came close to the Earth, and saw the ocean, the fish in it, the trees on land, the animals and the people, observed the rain and the sunshine, many different things, and he immediately realized something important. He made then brain wave-mail with the Director, communicating the following:

—…everything on this planet is linked to everything else, and in this sense everything has a meaning. The large surface extension of the oceans permits water to evaporate, this makes rain, rain makes plants grow with the help of sunshine, animals feed on plants, and plants produce oxygen, which is used by animal to breath, and oxygen is partly transformed into ozone, which shields animals from too much sunshine. And also – added the young green explorer with excitement – if you look at a single element, for example a tree, you will find a lot of meaning in its detailed structure: the roots are there to catch nutrients from the earth, the trunk is there to expose the leaves and fruits to the sun, the fruit is so constructed, that by falling on the earth it may liberate seeds for new plants, and so on. Everything is interconnected with each other in a web of meaning and purpose in all these actions and structures.

—You are talking here about meaning. The question was however about purpose... – answered briskly the old Green Man.

—Sorry, I was a little sloppy. Meaning has a more restricted dimension that purpose, it refers to a local context and does not have the implication of a larger goal.

—Let us go back to the basic question of purpose – interrupted again the old Green Man – What is the purpose of all this web of connections?

—This is life itself! There would be no life on this planet, if this web of connections would not exist. The purpose of nature is simply to keep life going on.

—To use your own words, this purpose is a mental construct of yours...

—Yes, Sir. But within this frame of mind, one can talk about purpose in nature.

—Does the web of connections also have a time component? – interrupted the old Green Man – Does it go somewhere – does it come from somewhere?

—Oh, yes! – said the green explorer – All parts of nature are linked to each other in a historical dimension as well. First of all there is a continuos reshuffling of molecular components from one generation to the other, in the sense that the components of the organisms which die are used up to construct the new generations. You see, Sir, there are practically no new molecules being made on this planet – except for a few coming with meteorites: there is a continuos recycling of old molecules, which are used up again and again to build all possible new organisms. Death is very important to give rise to birth. Thus, this web of connections goes all the way in the past and in the future. With evolution, every organism on this earth is linked to all generations before. Each living thing is in a way a historical product.

The old man smiled, it was not clear whether he was satisfied or simply amused.

—So, there is a purpose in nature, then! – he said – And this is life. Well...In a way, this is a fine proposition and also a rather poetic one. But you will agree with me that this is no real scientific answer. In fact, I can then ask: Why life started on Earth, and to what purpose? In other words: what is the purpose of life on Earth?


The young green explorer had thought of this question already and he could answer rather promptly...

—Concerning the first question – why and how life started on Earth – let me answer to you as a scientist from Earth would answer. He would say that we have first to free the field from the creationist interpretations, which are by definition not scientific. Once the idea of a Creator is eliminated, Sir, the answer to the first question – how all came about – is rather straightforward.

—And how is it?

—Consider first that once upon a time there was no life on Earth, there were only rocks and simple molecules. Then Life appeared. It follows, that life came from the inanimate matter: It is quite logical, isn't?

—Yes, it seems rather straightforward. – said the old green man – But how could life arise by from the inanimate matter? Isn’t that a case of spontaneous generation of life?

—In a way, yes, but on a scale range which stretches over many million years. The path starts most likely from simple molecular patterns of self-assembly and self-organization. Self-organized systems, once formed and stabilized, acquired eventually in the course of molecular evolution additional specific properties, for example self-replication and chemical catalysis. Thus, enzymes and nucleic acids were formed, and eventually the genetic code and the living cell. In this sense, Life is seen by scientists on Earth as a particular state of very complex self-organization. It is actually an emergent property of a particular state of self-organization, after complexity has reached a critical state.

—It is a nice story. But tell me: is all this ascertained experimentally, down there on Earth, or is it just a hypothesis? Are there clear experiments which show that life can emerge from non-life?

—It has not been ascertained experimentally, yet – the young Green Explorer had to admit – However, Sir, once you have eliminated the Creator, or the panspermia theory (life coming from other planets), no other possibility is left.

—I still do not see the link with the notion of purpose in Nature. Can you clarify for me this point?

—A living unity – repeated the young Green Man – comes equipped automatically with the autonomous task to maintain its own individuality, its own self. This task is part of the definition of life itself. A living unit does so by the mechanism of self-maintenance and self-generation from within, and there is a theory, the theory of autopoiesis, which describes this notion rather fully. Life is a process which constantly re-builds itself from the inside, utilizing for that simple products which diffuse inside the system throughout a so-called semi-permeable membrane. The membrane itself is a product of this life activity. A prokaryotic cell works this way, and also a tree, and also a cat. But no computer, no automobile, no dead cell, functions in this way.

—I may accept that. – answered the old Green Man – Thus, the purpose of every living organism is to keep itself alive and constant. But still: where does this purpose come from? Who imparted this idea on living creatures?

—This purpose is not given from outside, Sir, but it is self-generated. And I can say that this is indeed the great difference between a living organism and – say – a robot: a living system has a self-generated purpose of keeping itself alive. With the emergence of life, it comes the defense of the self-identity.


—Let me go back to the question of evolution, and to the relation between evolution and purpose in nature. Can one say that evolution – more than life itself – is the main purpose of nature? For example, do scientists on Earth accept the view that one of the purpose of Nature’s evolution has been the production of men?

—Not at all, Sir. It is actually assumed that man has been a chance product of biological evolution. Man might also have not been. After all, Earth has been populated for over three quarters of its history by bacteria alone…

—Thus, evolution simple moves forwards driven by pure chance?

—Not quite: one believes that it is not pure chance, in the sense that there are quite a few obligatory pathways – but then it is chance which determines which pathway is chosen.

—A pathway chosen without any aim, any purpose. Is this what you want to say?

—If by purpose we intend a teleonomy, a plan of nature, then yes, Sir, there is no purpose in evolution. This is what scientists on Earth assume.

—Let me understand better, my young man, the relation between life maintenance and evolution. It seems to me that the purpose of life, to maintain the identity of the organism, is almost denied by the evolutionist tendencies. Evolution is a force towards change, and therefore against the self-maintenance. Right?

—No, Sir, with your permission, this is not what I have understood from Earth biology. For example the so-called Santiago school maintains that the main force is actually self-maintenance. A colony of bacteria, for example, when exposed to climatic changes, is forced to accept some mutation, but it does so unwillingly, in order to survive. What drives evolution is not the search for change at any cost – on the contrary, it is the tendency to change as little as possible in order to defend the self-identity. Evolution, in this sense, is only a strategy for survival.


—I may accept that too, but I still need clarification about one point. – the Green Old Man was now smiling – I agree with you that an observer can attribute a purpose to nature, the purpose being the self-maintenance. But you confuse two levels here, namely the overall level of nature as defined by an external observer and the level of one single living organism. Why is self-maintenance of a single organism a "purpose"? The largest part of the living organisms are not aware to be living.

The young Green Man tried to think faster than usual:

—Certainly self-maintenance is instinctual at the level of an ameba, or of a tree, or a cat even. But it becomes different when the organism becomes aware of his own existence, namely at the level of consciousness. This is certainly so at the level of men, although it may be true for other higher animals as well. When the organism becomes aware of its own existence, it becomes aware of the purpose of life...

—Which, as you said before, is life itself...

—Yes Sir! – now the young Green Man had acquired more security – Being aware of his own life, man can choose an action instead of another, and work for a certain finality. Thus, life acquires a purpose. Furthermore, he acquires new values, like morality, responsibility, spirituality...Those values can be seen as a purpose in life.

—But you said before that purpose is self-generated.

—Yes, it is so. Morality for example is a self-generated value in humans, a value which arises once a critical level of human evolution has taken place.

—Then, morality, and even the belief in God, are self-generated values, and therefore self-generated life purposes. And it is consciousness, which in turn is a property generated by a certain degree of structural complexity, which produces life’ purpose.

The young Green Man said nothing for a while. He had now the feeling to have passed the examination, and decided to provoke the old man:

—The way you say it, Sir, is not quite as I mean it. There is a subtle difference. When you say that consciousness and morality arise as a consequence of a given structural complexity, you give the impression that those things are produced by matter – that the molecular structures produce for example morality.

—Is it not so? – asked the old Green Man grudgingly.

—The way I understood it, it goes rather this way: that the structures – the organisms – are in continuos contact with the environment through the so-called coupling interactions (I use the terminology of the so-called Santiago theory, Sir). This continuos stimulation from the environment produces thoughts which in turn modify the organism. It is circular logic more than a linear causality from matter to thought. Somebody over there on Earth likes better the term double causality – one arrow going from structure to thought, and one arrow going from thoughts to structure. I wanted to say, Sir, that it is not simply a mechanical causality which brings about consciousness, morality, religiosity. The human being is actually shaping his own life by continuously interacting with the environment, which includes the society itself.

—Hum! The turning point is here then the arising of consciousness. At this point, morality and its practical counterpart, responsibility, arise – and with this, also a new dimension of the purpose in life. I come back again however to my previous question, namely how this human level of purpose has anything to do with purpose in Nature.

—It does, Sir. In fact, the main purpose in life of conscient beings should be to respect the life purpose of nature – to keep life going on on the planet. Thus, men on Earth should in principle regulate their life responsibly so as to comply with nature’ purpose – to keep life going on on their planet.

—I read reports which were relating destruction of forests and pollution of ocean water and pollution of atmosphere. – said the old Green Man. – So, why they do so? Is destruction also a purpose of mankind?

—In a way, yes, Sir. In fact, one of the main self-imposed purpose in life of many people down there on Earth is to acquire power and welfare. To do so, groups of people optimize their own interest at the expenses of mankind at large – and start wars – or at the expenses of nature in a series of short range development projects. In this way, they tend to destroy the main project of nature – to keep life going on in peaceful equilibrium. There are rumors, Sir – the young Green Man was somewhat unwilling to say that – that people on Earth may destroy life on their own planet.

—And this is also a product of consciousness, isn’t? Lower animals do not do anything of this sort.

—Yes Sir, but lower animals do not build cathedrals and do not make art...

—Granted. So the question is which side of consciousness will win. What do you think, young man?