The Prigogine Medal was established in 2004 by the University of Siena and the Wessex Institute to honour the memory of Prof Ilya Prigogine, Nobel Prize winner for chemistry.
Ilya Prigogine was born in Moscow in 1917, and obtained his undergraduate and graduate education in Chemistry at the Free University in Brussels.
He was awarded the Nobel Prize for his contribution to non-equilibrium thermodynamics, particularly the theory of dissipative structures. The main theme of his scientific work was the role of time in the physical sciences and biology.
He contributed significantly to the understanding of irreversible processes, particularly in systems far from equilibrium. The results of his work have had profound consequences for understanding biological and ecological systems.
Prigogine’s ideas established the basis of ecological systems research. The Prigogine medal to honour his memory is awarded annually to a leading scientist in the field of ecological systems. All recipients have been deeply influenced by Prigogine’s work
Autobiography of Ilya A. Prigogine (1917 - 2003)
Winner of the Nobel Prize in Chemistry 1977
The following is taken from a translation of Prigogine’s French language autobiography
I was born in Moscow, on the 25th of January 1917—a few months before the revolution. My family had a difficult relationship with the new regime, and so we left Russia as early as 1921. For some years (until 1929), we lived as migrants in Germany, before we stayed for good in Belgium. It was at Brussels that I attended secondary school and university. I acquired Belgian nationality in
My father, Roman Prigogine, who died in 1974, was a chemical engineer from the Moscow Polytechnic. My brother Alexander, who was born four years before me, followed, as I did myself, the curriculum of chemistry at the Université Libre de Bruxelles.
I remember how much I hesitated before choosing this direction; as I left the classical (Greco- Latin) section of Ixelles Athenaeum, my interest was more focused on history and archaeology, not to mention music, especially piano. According to my mother, I was able to read musical scores before I read printed words. And, today, my favourite pastime is still piano playing.
In 1941, I was conferred my first doctoral degree. Very soon, two of my teachers were to exert an enduring influence on the orientation of my future work.
I would first mention Théophile De Donder (1873–1957). After 1918, he was promoted to Professor at the Department of Applied Science and began writing a course on theoretical thermodynamics for engineers. It is with this very circumstance that we have to associate the birth of the Brussels thermodynamics school.
In order to understand fully the originality of De Donder’s approach, I have to recall that since the fundamental work by Clausius, the second principle of thermodynamics has been formulated as an inequality: ‘uncompensated heat’ is positive—or, in more recent terms, entropy production is positive. This inequality refers, of course, to phenomena that are irreversible, as are any natural processes. In those times, these latter were poorly understood. They appeared to engineers and physicochemists as ‘parasitic’ phenomena, which could only hinder something: here the productivity of a process, there the regular growth of a crystal, without presenting any intrinsic interest. So, the usual approach was to limit the study of thermodynamics to the understanding of equilibrium laws, for which entropy production is zero.
This could only make thermodynamics a ‘thermostatics’. In this context, the great merit of De Donder was that he extracted the entropy production out of this ‘sfumato’ when he related it in a precise way to the pace of a chemical reaction, through the use of a new function that he was to call
It is difficult today to give an account of the hostility that such an approach was to meet. Fortunately, some eminent scientists derogated this negative attitude. I received much support from people such as Edmond Bauer, the successor to Jean Perrin at Paris, and Hendrik Kramers in Leyden.
De Donder, of course, had precursors, especially in the French thermodynamics school of Pierre Duhem. But in the study of chemical thermodynamics, De Donder went further, and he gave a new formulation of the second principle, based on such concepts as affinity and degree of evolution of a reaction, considered as a chemical variable.
Given my interest in the concept of time, it was only natural that my attention was focused on the second principle, as I felt from the start that it would introduce a new, unexpected element into the description of physical world evolution. A huge part of my scientific career would then be devoted to the elucidation of macroscopic as well as microscopic aspects of the second principle, in order to extend its validity to new situations, and to the other fundamental approaches of theoretical physics, such as classical and quantum dynamics.
I would also like to stress the influence on my scientific development that was exerted by the second of my teachers, Jean Timmermans (1882–1971). He was more an experimentalist, specially interested in the applications of classical thermodynamics to liquid solutions, and in general to complex systems, in accordance with the approach of the great Dutch thermodynamics school of van der Waals and Roozeboom.
In this way, I was confronted with the precise application of thermodynamical methods, and I could understand their usefulness. In the following years, I devoted much time to the theoretical approach of such problems, which called for the use of thermodynamical methods; I mean the solutions theory, the theory of corresponding states and of isotopic effects in the condensed phase. A collective research with V. Mathot, A. Bellemans and N. Trappeniers has led to the prediction of new effects such as the isotopic demixtion of helium He3 + He4, which matched in a perfect way the results of later research.
Among all those perspectives opened by thermodynamcis, the one which was to keep my interest was the study of irreversible phenomena, which made so manifest the ‘arrow of time’. From the very start, I always attributed to these processes a constructive role, in opposition to the standard approach, which only saw in these phenomena degradation and loss of useful work. The fact is that it appeared to me that living things provided us with striking examples of systems which were highly organized and where irreversible phenomena played an essential role.
Such intellectual connections, although rather vague at the beginning, contributed to the elaboration, in 1945, of the theorem of minimum entropy production, applicable to non-equilibrium stationary states. This theorem gives a clear explanation of the analogy which related the stability of equilibrium thermodynamical states and the stability of biological systems, such as that expressed in the concept of ‘homeostasy’ proposed by Claude Bernard. This is why, in collaboration with J.M. Wiame, I applied this theorem to the discussion of some important problems in theoretical biology, namely to the energetics of embryological evolution. As we better know today, in this domain the theorem can at best give an explanation of some ‘late’ phenomena, but it is remarkable that it continues to interest numerous experimentalists.
From the very beginning, I knew that the minimum entropy production was valid only for the linear branch of irreversible phenomena, the one to which the famous reciprocity relations of Onsager are applicable. And, thus, the question was: What about the stationary states far from equilibrium, for which Onsager relations are not valid, but which are still in the scope of macroscopic description? Linear relations are very good approximations for the study of transport phenomena (thermical conductivity, thermodiffusion, etc.), but are generally not valid for the conditions of chemical kinetics. Indeed, chemical equilibrium is ensured through the compensation of two antagonistic processes, while in chemical kinetics—far from equilibrium, out of the linear branch—one is usually confronted with the opposite situation, where one of the processes is negligible.
Notwithstanding this local character, the linear thermodynamics of irreversible processes had already led to numerous applications, as shown by people such as J. Meixner, S.R. de Groot and P. Mazur, and, in the area of biology, A. Katchalsky. It was for me a supplementary incentive when I had to meet more general situations. Those problems had confronted us for more than twenty years, between 1947 and 1967, until we finally reached the notion of ‘dissipative structure’. During this phase of my work, the original and enthusiastic mind of my colleague Paul Glansdorff played a major role.
Our collaboration was to give birth to a general evolution criterion which is of use far from equilibrium in the non-linear branch, out of the validity domain of the minimum entropy production theorem. Stability criteria that resulted were to lead to the discovery of critical states, with branch shifting and possible appearance of new structures. This quite unexpected manifestation of ‘disorder– order’ processes, far from equilibrium, but conforming to the second law of thermodynamics, was to change in depth its traditional interpretation. In addition to classical equilibrium structures, we now face dissipative coherent structures, for sufficient far-from-equilibrium conditions.
In a first, tentative step, we thought mostly of hydrodynamical applications, using our results as tools for numerical computation. Here the help of R. Schechter from the University of Texas at Austin was highly valuable. Those questions remain wide open, but our centre of interest has shifted towards chemical dissipative systems, which are more easy to study than convective processes.
All the same, once we formulated the concept of dissipative structure, a new path was open to research and, from this time, our work showed striking acceleration. This was due to the presence of a happy meeting of circumstances, mostly due to the presence in our team of a new generation of clever young scientists. I cannot mention here all those people, but I wish to stress the important role played by two of them, R. Lefever and G. Nicolis. It was with them that we were in a position to build up a new kinetical model, which would prove at the same time to be quite simple and very instructive—the ‘Brusselator’, as J. Tyson would call it later—and which would manifest the amazing variety of structures generated through diffusion–reaction processes.
It was only quite a while later that I recalled the comments by A. Turing on those questions of stability, as, perhaps too concerned about linear thermodynamics, I was then not receptive enough.
Let us go back to the circumstances that favoured the rapid development of the study of dissipative structures. The attention of scientists was attracted to coherent non-equilibrium structures after the discovery of experimental oscillating chemical reactions such as the Belusov–Zhabotinsky reaction; the explanation of its mechanism by Noyes and his co-workers; the study of oscillating reactions in biochemistry (for example, the glycolytic cycle, studied by B. Chance and B. Hess) and eventually the important research led by M. Eigen. Therefore, since 1967, we have been confronted with a huge number of papers on this topic, in sharp contrast with the total absence of interest which prevailed during previous times.
But the introduction of the concept of dissipative structure was also to have other unexpected consequences. It was evident from start that the structures were evolving out of fluctuations. They appeared in fact as giant fluctuations, stabilized through matter and energy exchanges with the outer world. Since the formulation of the minimum entropy production theorem, the study of non-equilibrium fluctuation had attracted all my attention. It was thus only natural that I resumed this work in order to propose an extension of the case of far-from-equilibrium chemical reactions.
This subject I proposed to G. Nicolis and A. Babloyantz. We expected to find for stationary states a Poisson distribution similar to the one predicted for equilibrium fluctuations by the celebrated Einstein relations. Nicolis and Babloyantz developed a detailed analysis of linear chemical reactions and were able to confirm this prediction. They added some qualitative remarks which suggested the validity of such results for any chemical reaction.
Considering again the computations for the example of a non-linear biomolecular reaction, I noticed that this extension was not valid. A further analysis, where G. Nicolis played a key role, showed that an unexpected phenomenon appeared while one considered the fluctuation problem in non-linear systems far from equilibrium: the distribution law of fluctuations depends on their scale, and only
‘small fluctuations’ follow the law proposed by Einstein. After a prudent reception, this result is now widely accepted, and the theory of non-equilibrium fluctuations is fully developing now, so as to allow us to expect important results in the following years. What is already clear today is that a domain such as chemical kinetics, which was considered conceptually closed, must be thoroughly rethought, and that a brand new discipline, dealing with non-equilibrium phase transitions, is now appearing.
Progress in irreversible phenomena theory leads us also to reconsideration of their insertion into classical and quantum dynamics. Let us take a new look at the statistical mechanics of some years ago. From the very beginning of my research, I had had occasion to use conventional methods of statistical mechanics for equilibrium situations. Such methods are very useful for the study of thermodynamical properties of polymer solutions or isotopes. Here we deal mostly with simple computational problems, as the conceptual tools of equilibrium statistical mechanics have been well established since the work of Gibbs and Einstein. My interest in non-equilibrium would by necessity lead me to the problem of the foundations of statistical mechanics, and especially to the microscopic interpretation of irreversibility.
Since the time of my first graduation in science, I was an enthusiastic reader of Boltzmann, whose dynamical vision of physical becoming was for me a model of intuition and penetration. Nonetheless, I could not but notice some unsatisfying aspects. It was clear that Boltzmann introduced hypotheses foreign to dynamics; under such assumptions, to talk about a dynamical justification of thermodynamics seemed to me an excessive conclusion, to say the least. In my opinion, the identification of entropy with molecular disorder could contain only one part of the truth if, as I persisted in thinking, irreversible processes were endowed with this constructive role I never cease to attribute to them. For another part, the applications of Boltzmann’s methods were restricted to diluted gases, while I was most interested in condensed systems.
At the end of the forties, great interest was aroused in the generalization of kinetic theory to dense media. After the pioneering work by Yvon, publications of Kirkwodd, Born and Green, and of Bogoliubov attracted a lot of attention to this problem, which was to lead to the birth of non- equilibrium statistical mechanics. As I could not remain alien to this movement, I proposed to G. Klein, a disciple of Fürth who came to work with me, to try the application of Born and Green’s method to a concrete, simple example, in which the equilibrium approach did not lead to an exact solution. This was our first tentative step in non-equilibrium statistical mechanics. It was eventually a failure, with the conclusion that Born and Green’s formalism did not lead to a satisfying extension of Boltzmann’s method to dense systems.
But this failure was not a total one, as it led me, during a later work, to a first question: Was it possible to develop an ‘exact’ dynamical theory of irreversible phenomena? Everybody knows that according to the classical point of view, irreversibility results from supplementary approximations
to fundamental laws of elementary phenomena, which are strictly reversible. These supplementary approximations allowed Boltzmann to shift from a dynamical, reversible description to a probabilistic one, in order to establish his celebrated H theorem.
We still encountered this negative attitude of ‘passivity’ imputed to irreversible phenomena, an attitude that I could not share. If—as I was prepared to think—irreversible phenomena actually play an active, constructive role, their study could not be reduced to a description in terms of supplementary approximations. Moreover, my opinion was that in a good theory a viscosity coefficient would present as much physical meaning as a specific heat, and the mean life duration of a particle as much as its mass.
I felt confirmed in this attitude by the remarkable publications of Chandrasekhar and von Neumann, which were also issued during the forties. That was why, still with the help of G. Klein, I decided to take a fresh look at an example already studied by Schrödinger, related to the description of a system of harmonic oscillators. We were surprised to see that, for all such a simple model allowed us to conclude, this class of systems tend to equilibrium. But how to generalize this result to non-linear dynamical systems?
Here the truly historic performance of Léon van Hove opened for us the way (1955). Some of his works had a lasting effect on the whole development of statistical physics; I mean not only his study of the deduction of a ‘master equation’ for anharmonic systems, but also his fundamental contribution on phase transitions, which was to lead to the branch of statistical mechanics that deals with so- called ‘exact’ results.
This first study by van Hove was restricted to weakly coupled anharmonic systems. But, anyway, the path was open, and with some of my colleagues and collaborators, mainly R. Balescu, R. Brout, F. Hénin and P. Résibois, we achieved a formulation of non-equilibrium statistical mechanics from a purely dynamical point of view, without any probabilistic assumption. The method we used is summed up in my 1962 book. It leads to a ‘dynamics of correlations’, as the relation between interaction and correlation constitutes the essential component of the description. Since then, these methods have led to numerous applications.
This concluded the first step of my research in non-equilibrium statistical mechanics. The second is characterized by a very strong analogy with the approach of irreversible phenomena which led us from linear thermodynamics to non-linear thermodynamics. In this tentative step also, I was prompted by a feeling of dissatisfaction, as the relation with thermodynamics was not established by our work in statistical mechanics, nor by any other method. The theorem of Boltzmann was still as isolated as ever, and the question of the nature of dynamic systems to which thermodynamics applies was still without answer.
The problem was by far more wide and more complex than the rather technical considerations that we had reached. It touched the very nature of dynamical systems, and the limits of Hamiltonian description. I would never have dared approach such a subject if I had not been stimulated by discussions with some highly competent friends such as the late Léon Rosenfeld from Copenhagen, or G. Wentzel from Chicago. Rosenfeld did more than give me advice; he was directly involved in the progressive elaboration of the concepts we had to explore if we were to build a new interpretation of irreversibility. More than any other stage of my scientific career, this one was the result of a collective effort. I could not possibly have succeeded had it not been for the help of my colleagues M. de Haan, Cl. George, A. Grecos, F. Henin, F. Mayné, W. Schieve and M. Theodosopulu. If irreversibility does not result from supplementary approximations, it can only be formulated in a theory of transformations which expresses in ‘explicit’ terms what the usual formulation of dynamics does ‘hide’. In this perspective, the kinetic equation of Boltzmann corresponds to a formulation of dynamics in a new representation.
In conclusion, dynamics and thermodynamics become two complementary descriptions of nature, bound by a new theory of non-unitary transformation. I came so to my present concerns; and, thus, it is time to end this intellectual autobiography. As we started from specific problems, such as the thermodynamic signification of non-equilibrium stationary states, or of transport phenomena in dense systems, we have been faced, almost against our will, with problems of great generality and complexity, which call for reconsideration of the relation of physicochemical structures to biological ones, while they express the limits of Hamiltonian description in physics. Indeed, all these problems have a common element: time.
The research conducted with my friend R. Herman on the theory of car traffic gave me confirmation of the supposition that even human behaviour, with all its complexity, would eventually be susceptible of a mathematical formulation. In this way the dichotomy of the ‘two cultures’ could and should be removed. There would correspond to the breakthrough of biologists and anthropologists towards the molecular description or the ‘elementary structures’, if we are to use the formulation by Lévi- Strauss, a complementary move by the physicochemist towards complexity. Time and complexity are concepts that present intrinsic mutual relations.
During his inaugural lecture, De Donder spoke in these terms: ‘Mathematical physics represents the purest image that the view of nature may generate in the human mind; this image presents all the character of the product of art; it begets some unity, it is true and has the quality of sublimity; this image is to physical nature what music is to the thousand noises of which the air is full … .’
Filtrate music out of noise; the unity of the spiritual history of humanity, as was stressed by M. Eliade, is a recent discovery that has still to be assimilated. The search for what is meaningful and true by opposition to noise is a tentative step that appears to be intrinsically related to the coming into consciousness of man facing a nature of which he is a part and which it leaves.
The work of a theoretician is related in a direct way to his whole life. It takes, I believe, some amount of internal peace to find a path among all successive bifurcations. This peace I owe to my wife, Marina. I know the frailty of the present, but today, considering the future, I feel myself to be a happy man.
Obituary of Professor Ilya A. Prigogine
By Prof Tiezzi, University of Siena, Italy
Last Christmas I received greetings for the new year from Bruxelles. I was surprised to see the name: Ilya Prigogine. It is usually the scholar who writes to the Magister and non vice versa.
A few years earlier, Ilya invited me and Nadia to his home in Bruxelles. I remember the marvellous collection of “time machines”: the ancient Maya, the Chinese masterpieces, Inca pieces. Ilya’s wife Marina and his son Pascal are people of rare kindness. After dinner we talked about cosmology, irreversibility and the arrow of time with a French scientist.
Nobel prize winner Ilya Prigogine, Viscount, professor of Physical Chemistry, came to Siena several times. We awarded him a Laurea Honoris Causa in Biological Sciences in the Aula Magna of Siena University. He noticed at the time that the University is one of the oldest in the world, founded in 1240.
For many years we exchanged Ph.D. students (or rather, students from Siena went to Bruxelles for a year). Now that he is no longer with us, I feel that we have lost not only a Magister but a brilliant young mind and a human being always friendly and kind. A friend, a very good friend.
I personally consider Ilya Prigogine the greatest scientist of the 20th century. He was awarded the Nobel Prize in chemistry in 1977 for his contributions to nonequilibrium thermodynamics, particularly the theory of dissipative structures. He was born in Moscow, Russia on January 25, 1917. He obtained both his undergraduate and graduate education in chemistry at the Université Libre de Bruxelles.
The main theme of his scientific work was the role of time in the physical sciences and biology. He has contributed significantly to the understanding of irreversible processes, particularly in systems far from equilibrium. The results of his work on dissipative structures have stimulated many scientists throughout the world and may have profound consequences for our understanding of biological and ecological systems.
In the Nobel Lecture (8 December, 1977) Prigogine wrote: “the development of the theory permits us to distinguish various levels of time: time as associated with classical or quantum dynamics, time associated with irreversibility through a Lyapounow function and time associated with ‘history’ through bifurcations. I believe that this diversification of the concept of time enables a better integration of theoretical physics and chemistry with disciplines dealing with other aspects of nature.”
As only a very intelligent person can do, he wrote an autobiography, which like his scientific career, was distinguished by a total absence of hypocritical respect. Here are some passages I found particularly significant:
“… Since my adolescence, I have read many philosophical texts, and I still remember the spell "L'évolution créatrice" cast on me. More specifically, I felt that some essential message was embedded, still to be made explicit, in Bergson's remark:
‘ The more deeply we study the nature of time, the better we understand that duration means invention, creation of forms, continuous elaboration of the absolutely new.’
Fortunate coincidences made the choice for my studies at the university. Indeed, they led me to an almost opposite direction, towards chemistry and physics. And so, in 1941, I was conferred my first doctoral degree. Very soon, two of my teachers were to exert an enduring influence on the orientation of my future work.
… It is difficult today to give an account of the hostility that such an approach was to meet. For example, I remember that towards the end of 1946, at the Brussels IUPAP meeting, after a presentation of the thermodynamics of irreversible processes, a specialist of great repute said to me, in substance: ‘I am surprised that you give more attention to irreversible phenomena, which are essentially transitory, than to the final result of their evolution, equilibrium.’
… The work of a theoretician is related in a direct way to his whole life. It takes, I believe, some amount of internal peace to find a path among all successive bifurcations. This peace I owe to my wife, Marina. I know the frailty of the present, but today, considering the future, I feel myself to be a happy man.”
Enzo Tiezzi, University of Siena, Italy
NOTE: Prof Ilya Prigogine, Honorary President of the ECOSUD Conference Series and Honorary Editor of the Book Series “The Sustainable World”.
Dialectic by M. Prigogine and T. Patterson
Upon the near collapse of the post-Kyoto meeting in Buenos Aires in December 2004, EU head delegate, Dutch environment secretary Pieter van Geel summarised, stating: 'A lot of people are afraid of discussing the future.' His words referred to the failure of the meeting’s intentions to determine worldwide cooperation to reduce global warming following the first 15 Kyoto years to 2012. These objectives failed in no small part due to policy’s demands on science with respect to certainty and measures of determinism. Social expectations such as these persist despite scientific advances, most notably made by Nobel Prize winner Ilya Prigogine and his numerous collaborators, which show that rigid dependence on these conditions does more to paralyse collective action than enable it. As a result, policy has yet to effectively harness the most powerful aspect of science with respect to resolving the major challenges of the global future-its creativity.
Ilya Prigogine laid scientific and philosophical foundations in the time-reversible, symmetric world of theoretical physics for rigorous study of irreversible, far-from-equilibrium phenomena, such as that of living systems and therefore the frontiers of theoretical ecology. As such, his work ethic, creative drive and ethos provide a beacon for those who would combine ecological theory with evolutionary physics. Here, his wife, Maryna Prigogine discusses with Trista Patterson, a post-doctoral researcher in Ecodynamics at the Italian University of Siena, issues of ecological theory and Prigogine’s future creative.
This article takes an atypical scientific form. 'Dialectic' usually refers to either the Socratic method of cross-examination, Hegel’s model of history. 'Dialectics' can also refer to an understanding of how we can or should perceive the world (epistemology), an assertion of the interconnected, contradictory and dynamic nature of the world outside our perception of it (ontology), or a method of presentation of ideas or conclusions. The back-and-forth (dialectic) of causation implies a dynamic process and reflects the spirit of ecodynamics research.
T. Patterson: Thank you for your time, Madame Prigogine.
M. Prigogine: You’re welcome. I enjoyed my trip to Siena, Italy, to award the first Prigogine Medal in Ecodynamics.
T. Patterson: The Journal of Ecodynamics was initiated by a group of scientists who felt that advances in evolutionary physics were being complimented by recent advances in theoretical ecology, and that these synergies were among the most exciting advances in resolving major issues of global concern.
The time was right; they felt, to provide a venue for exchange of information which could support rigorous study of ecodynamics. Ecodynamics is the study of ecological complexity based in rigorous foundations such as the laws of thermodynamics. Your husband’s evolutionary approach, of course, is noted for being the origin of this line of research.
Your contribution continues to be valuable as you have been central to the organization and dissemination of your husband’s work throughout his life. More than a calculating look at the proofs he devised, I believe the editors asked me to consult you because a more intuitive approach to his work was desired. That kind of perspective, as you’re aware, is very difficult to bring out of a scientific document. Your contribution is seen as valuable to inspiring other contributions to the journal which emphasize creative and intuitive approaches—not just limited to pure science, but also to provide a venue which could be combined with art, philosophy, etc.
M. Prigogine: Yes, well, that ‘intuition’ was something incredible about my husband. Already in 1937 at the age of 20 in ‘Les Cahiers du Libre Examen’ (Cercle d’Etude de L’Université Libre de Bruxelles) he wrote:
Contemporary experiments in physics, biology and psychology show us the whole universe obeying deterministic law. But it is with some reluctance that our mind accepts this conclusion, one in such contradiction with our life experience that permits us to believe in the possibility of unarbitrary choice between different conduct. 
We see then that from the beginning he could not accept that the whole human experience would be in contradiction with the fundamental laws of nature which were deterministic and reversible in time. And the quest for an answer to this problem became the centre of his search during all his life.
T. Patterson: (laughs) Well, I suppose there’s a lesson there, but of course, it takes courage to discuss ideas at the age of 20 when you are not sure how to go about the proof of what you intuitively know to be true. There’s a courage in that, and personal conviction, he wrote frequently of passion in science stating:
People tend to think of science as something very dry and dispassionate, but there is a great deal of passion involved … I have always thought that science has two aspects: to understand the world around us but also to understand our own position in the world. The latter problem in particular can never be a neutral one.We are involved in scientific research like we are involved in a political movement. Passion is as much a part of science as it is of politics.—I. Prigogine 
M. Prigogine: Oh good, so you’ve read that article. Yes, he believed in the role of passion in processing knowledge. This seems to be a paradox as science by definition is beyond passion. He wrote ‘… how can we accept as Einstein did, the idea that determinism reigns absolute and at the same time the idea that the creation of theory is due to the free play of the human mind? I think this is an example of an emotional attitude that clearly marks the limits of reason.’ 
T. Patterson: Do you suspect that this kind of courage, passion, etc., is what is needed for science to contribute to overcoming the major social roadblocks of our time? What comes to mind is your husband’s courage to speak about the future. I sent you that quote, I believe, from the close of the Kyoto meetings. I was discouraged that nothing happened there, and the contrast struck me that they said it was because people were afraid to speak of the future. Your husband didn’t seem to have that fear.
M. Prigogine: Well, no. But you know, nobody wants to accept the responsibility for forcing us to act in the way we should. It’s not popular! They are thinking about the very near future.
T. Patterson: Your husband had some interesting things to say about the distant future, surprising, I found especially with respect to utopias. Scientists don’t speak of utopias so frequently, but in his work they seemed to have a very definite role:
The future of mankind is most often seen in one of two ways. One view is that mankind is making progress with respect to self-determination and human dignity, etc. The other view is that mankind is running straight toward catastrophe. I believe that both attitudes are too extreme and have to be corrected. We do not live in a deterministic system. We cannot extrapolate from our present state what the future will bring …
I prefer to look at this question a different way. I believe that what we do today depends on our image of the future, rather than the future depending on what we do today. We build our equations by our actions. These equations, and the future they represent, are not written in nature. In other words, time becomes construction. Of course, we have some conditions that determine limits of the future but within these limits are many, many possibilities …Therefore, since no deterministic prediction is likely to be valid, visions of the future—utopian visions—play a very important role in present conduct …
I like very much the fact that instability opens up a horizon of possibilities, since our actions at a given time depend on the way in which we view the future. If we looked on the horizon and saw only death, pollution and decay, I think it would erase any argument for reasoned, ethical action today.
I am more afraid of the lack of utopias. —I. Prigogine 
M. Prigogine: Yes that’s exactly it. Furthermore, he really believed in the role of the individual, the role of everybody to imagine and take part in acting which creates the future. This conviction came from his study of the behaviour of systems far from equilibrium. He showed that far from equilibrium complex systems are capable of creation of the new structures. There are many possibilities, but only one is realized. And the kind of bifurcation realized depends strongly on the fluctuation realized. And here we come to the role of individuals in creating the conditions which would permit the bifurcation that will bring us to the future which we would like to have.
T. Patterson: Some have cited as your husband’s work as evidence of freedom and ethical responsibility in an asymmetric universe. I remember in another of his articles, he seemed to speak directly to young researchers, emphasizing the difference between being and becoming. I wonder if this isn’t at the core of how uncertainty paralyzes society in working for future collective good. Do you think it’s that the idea of being is something definite, tangible and becoming—the mechanisms and one’s role in how the future comes about is so much less clear? He wrote ‘I try to work out the transition between being Being and Becoming—Being is always a stage of Becoming’ . He thus referenced the role of bifurcations throughout history, and the importance of individual action in instability. At that time he was referring to social fluctuations and microscopic structures which precipitated major world events—but it seems this idea could be applied to so many contemporary realities.
The world is based on probability and the history of society is most definitely based on probability.
The hope I would like to give young people is that probability lends importance to these fluctuations. History is not made, it is being made. …history is still in its early stages—we only have 10,000 years of history. Man will change; man is only at his early stage. There are still so many people who have no involvement in their culture, who are still hungry. Is this necessary, is it inevitable? I don’t believe it is. … it is important that young people play a greater role. They must fight against resignation and the sense of powerlessness.
M. Prigogine: Well, being and becoming, that is a difficult, difficult issue. He was very certain in his ideas of utopias. It’s not a linear development, you know. When you say you want to go somewhere, it’s never direct … He insisted that the young would have the conviction … ‘you must believe’. He was speaking and believing that each one person must take their own responsibility. You see, he pursued his ideas because he believed that the reality in which he lived (following the Russian revolution, the son of a family who had to emigrate from Russia) was not the only possible reality, that it could be influenced in a different way and give a different bifurcation. I think Einstein and my husband lived at roughly the same time, and was exposed to many of the same conditions. It is amazing that they turned out so differently. Einstein was a pessimist, he used science as a way to escape the world; he used it as a way to escape realities. My husband was totally opposite. He wanted to change the world as it was.
T. Patterson: I’ve heard people say that your husband had Einstein rolling in his grave! Their views were so different; where did he get that courage? Did your husband have to think Einstein was out of his mind with his ideas?
M. Prigogine: No, no! On the contrary! He had a great admiration for Einstein, you know. And he also had a great regret. One of his friends at University asked him once if he wanted to meet Einstein, and he said ‘Oh, yes!’…they went to the University, but when they got to the door he thought, and changed his mind. He went home instead, thinking ‘I’m not prepared to discuss with him’, and turned away, thinking ‘I will do it next time’… But then you know ‘the next time’ never came, because Einstein died. Yes, I suppose there’s a lesson there.
T. Patterson: For procrastinators like myself, I suppose (laughs). Let’s go back a bit. I want to clarify something…you’d said your husband cited Aristotle, Newton, Laplace, Einstein, Kant,1 especially when it seemed he felt that social policy was demanding and/or relying too much on science for determined, certain, objective answers. When, in fact, his work proved that the laws of nature were, in effect, creative, and irreversible processes that played an active rather than parasitic role. In the lectures you sent me he would state:
Laws of nature are no more leading to certitudes, the only express ‘possibilities’. In the early stage of the world the world was like a small child which could become a musician, lawyer or whatsoever, but not all at the same time. Similarly, the laws of nature whether they are 1 See also Tiezzi  p. 10 for a more complete discussion of epistemology, science and technoscience, and Tiezzi for a discussion of the deterministic and mechanistic theories in driving ecological deterioration in the 20th century. classical, quantum or relativistic are no longer expressing deterministic situations, they express possibilities … there are not only laws, but also events. and
The world is a historical world, that there are instabilities, fluctuations, going on at all levels…
Nature is not only a geometry, it contains a narrative element, more like a novel … Time is a ‘construction’, and being a construction, creativity becomes part of the laws of nature, something in which we participate. 
If the role of the scientist is traditionally thought to be one of cold, calculating, dispassionate objectivity, this couldn’t have been an easy position for him to take….
M. Prigogine: Yes, of course not! The idea that laws of nature are no more leading to certitude but that they only expresses possibilities is still not easy to accept for some scientists. As far as we go to the past, as soon as the conscience appeared in the human mind, humans became anxious about the future. The deterministic laws gave us a sense that it was possible to foresee the future. This is certainly one of the reasons why Newton’s law was so well accepted.
T. Patterson: Do you think that this natural difficulty in taking personal responsibility is why scientists are often reluctant to adopt the creative role necessary to resolve the theoretical problems posed to the future by environmental crisis? I mean, doesn’t it seem there are two extremes between which one is trapped? Either one is believing that they are insignificant and therefore can’t do anything, or one is fearful of the power and responsibility one would have if they could bring about the deepest change?
You’d mentioned a few moments ago that social action was blocked because of fear of unpopular decisions….Madame Prigogine, on the occasion of the first Prigogine Awards, presenting the Medal to Professor Jørgenson.
M. Prigogine: Yes, well, fear of that and fear of the future. It’s a cultural attribute, one which can only be described by comparing different cultures. My husband was always very interested in other civilizations, particularly pre-Columbian.
Pre-Colombian peoples believed that the world was created by self-sacrifice of the gods. This sacrifice created the world, it’s sustained it and as it sustained it, it transformed it. But their gods were not strong, they had to be helped by peoples. The Mesoamericans were obsessed by the responsibility for keeping the cosmos in movement. They believed that the universe was in eternal danger of stopping, and thus perishing. To avoid this catastrophe man must’ve nourished the sun with his blood. The gods needed the human beings as the human beings needed the gods. Anxiety and fear are principle images in their art, so you can see many many examples of it. They believed, in the constructive role of time and in their role to influence the world. The Chinese vision of the world was completely different. The very existence of deterministic laws had no place in Chinese thought. To think of nature as submissive to universal, deterministic laws seemed to many ancient Chinese scholars as a contradiction in terms. They shared the common Chinese view of natural processes as something spontaneous, submissive only to internal regulation. In this context, Chinese scholars thought of the man–nature relationship in terms of resonance or coexistence more than in terms of control or domination. The very confirmation of this relation you can find in Chinese art—in the place which is given to the human being in the painted landscape for example. The association of nature with the idea of complexity was very strong in Chinese tradition and was very near to the vision of my husband. This is probably the reason why when he was invited in 1980 to give the series of lectures, after the first lecture, they told him that he was not to explain from the beginning because they already knew it. They asked him to speak about more recent work.They were more attuned to his work than we had imagined. Now, speaking about European culture, traditionally in European culture we have developed the idea of a strong god. Humans were considered somewhere between nature and god, a sort of place of privilege. There was this belief that god was protecting us. This is why it was so well accepted—the deterministic vision of the world, Newton’s laws, etc. It was very comfortable and gave a great impression of security. However, today the modern science suggests a different conception of the world which is curiously much nearer to the beliefs of pre-Columbian peoples, the conception in which a human being is no more considered an automaton with no responsibility but rather a part of nature with the capacity to influence nature and to create a new future. Also, more recently we are seeing an emergence of interest in the study of complexity of nature in European science, in part bringing it nearer to the perspective the Chinese have long held. My husband identified very much with the harmony of their approach.
T. Patterson: I’ve heard that when written in Chinese, the word ‘crisis’ is composed of two characters— the first one represents danger and the second one represents opportunity.
M. Prigogine: Why yes, I think my husband would have agreed very much in this description, that any given event is capable of becoming a catastrophe or something wonderful. I think he would’ve liked this description very much indeed.
Anyway, there are influences and applications of the work of my husband in many fields. Recently we had a wonderful meeting organized by the Solvay Institute (Bruxelles) to commemorate him. All of his colleagues from throughout his lifetime came—people that I hadn’t seen in 20 years! And the applications and connections are being made in all different fields, philosophy, art, social sciences…it’s amazing. I think the connections will go on for a long time, there are many questions.
You know, my husband said to me five days before he died ‘You know, I wasn’t so gifted. I took
50 years to prove the ideas I had when I was 20.’…
T. Patterson: Well that certainly puts the tasks at hand in perspective, doesn’t it?
M. Prigogine: (laughs) Yes, well, there is a lot to do.
Bertrand Russell, in his ‘History of Western Philosophy ‘wrote ‘To teach how to live without certainty, and yet without being paralyzed by hesitation, is perhaps the chief thing that philosophy in our age can still do for those who study it.’ In this light, probably one of the greatest ecological philosophers was one who was not known to be an ecologist at all. Ilya Prigogine bridged the gap between the old determinacy of physical science (laws extending from non-living, reversible, closed systems) and the new indeterminacy of complex, living, irreversible, systems. In doing so, he offered an alternative way to reconcile the findings of prior notable physicists with the living, dynamical, far from equilibrium realities of our world.
The work Ilya Prigogine left behind is fundamental to the greatest ecological challenges yet to be advanced. We began this interview speaking about the intuitive approaches which might break the paralysis that uncertainty places on collective social action, and have discussed some of the ways Ilya Prigogine appreciated the different facets of these questions. He saw the world as somewhere between a deterministic world (completely governed by laws) and a completely arbitrary world (completely governed by events), the events being a combination of probability and irreversibility. Irreversibility, Prigogine explained, is the origin of free will, creativity and novelty, and thus, life. Despite the findings of Prigogine and those after him, emphasis is still placed in perfect certainty.
Science has a continuing battle to do with the mistaken assertion that all partial truths are in the end compatible, that they are part of a universal rational predetermined certainty. Science must actively assist policy in striking the balance between personal freedom and social good, and that the dynamics of events and evolution must be accounted for in adjusting political decisions to both. Prigogine felt from an early age that determinism did not describe well the conditions of life. His work reminds us of the importance of each person in creating conditions, contributing to fluctuations and bearing witness to the bifurcations which lead to futures we can now only conceive of as utopia. The difference is between basing the laws of nature on possibilities versus on certitudes. This is no trivial difference for using ecological theory to construct the present and confront the future.
This challenge requires emphasis on process versus emphasis on structure, non-equilibrium over equilibrium, evolution versus permanency, individual creativity over collective stabilization. There is a slightly odd notion in environmental science today that things are moving so fast that ecological theory, as a strategy, becomes an obsolete idea. That everything is determined and all we need as humans to be is flexible or adaptable. This is a mistake. One cannot substitute agility for strategy. If ecological theorists do not look to the future and shed light on a strategy with respect to the world’s biological resources, humanity faces the future with an abbreviated set of starting conditions from which the future will arise. Without the benefit of ecological theory, inadequate or no value at all is assigned to crucial, complex and powerful interdependencies among species. As it inclines to be only reactive (not proactive) to external circumstances, ecology emerges as an ever less powerful science.
In the 21st century, the scientific imagination has potential to heal this rift. Ilya Prigogine has demonstrated that creativity in nature leads, through infinite bifurcations or decision points, to an unforetold plurality of possibilities, not a predestined fate for man or molecule. There are objective laws and structures, to be sure, but there is also choice. Those choices, in society and nature, affect outcomes in complex interactions within ever changing structures in which everything is related to everything else. As Ilya Prigogine suggested, the model for the social sciences should be not be to deliver Newtonian laws for society, where according to Kant everything can be predicted, but rather to study and isolate the points of bifurcation.
For Prigogine, the utopian dreams of humans are thus an input in our future, not an incidental element. Millions of scientific research dollars and hours are spent on attempts to model and predict the future, rather than imagining preferred future options together.
At the very far edges of human knowledge, creativity is at work designing nature’s rules, and we have only just begun to explore them. Yet, uncertainty paralyzes reason’s steps toward the future.
Chained by certitudes, one forfeits the degrees of freedom necessary to envision a sustainable, desirable future on this planet. Without this vision, the only certainty that exists is that this reality will not come about. Time and complexity are concepts that present intrinsic mutual relations, thereby tying ourselves to each other, and to a future—one in which we all actively participate.
Prigogine Medal 2004: Sven E. Jørgensen, Denmark
Professor Sven Erik Jørgensen, Dr. Eng, Dr. Scient. is the first recipient of the Prigogine Medal. He was a leading worldwide authority in ecological systems until his departure in 2016.
Prigogine Medal 2005: Enzo Tiezzi, Italy
Prof Enzo Tiezzi of the University of Siena, is an internationally renowned scientist for his achievements in the field of ecological systems.
He is the author of more than 500 scientific papers, mostly published in prestigious international journals. His collaboration includes those with Ilya Prigogine, Howard Odum, Danilo Dolci, Edgar Morin, Herman Daly and Sven Jorgensen. His outstanding scientific career has been matched by a commitment to environmental and social issues.
Prigogine Medal 2006: Bernard Patten, USA
Bernard C. Patten is Regents Professor of Ecology at the University of Georgia, USA. He is a systems ecologist and ecological modeller, interested in the application of mathematical system theory to ecosystems.
Prigogine Medal 2007: Robert Ulanowicz, USA
Robert Ulanowicz’s impact in science is remarkable. It is not just a matter of scientific productivity, illustrated by more than 150 scientific papers in international journals and several books, as well as by his role as a member of the editorial board of more than half a dozen international journals.
Prigogine Medal 2008: Ioannis Antoniou, Greece
Ioannis Antoniou graduated from the Physics Department of the University of Athens. After graduation he worked in the Greek Ministry of the Environment on atmospheric pollution measurements and statistical analysis and went to Brussels for his PhD research, where Ilya Prigogine was one of his PhD advisors.
Prigogine Medal 2009: Emilio del Giudice, Italy
Professor Del Giudice’s research interests are focused on Quantum Field Theory with reference to the investigation of collective processes and living organisms, as well as the structure of liquid water.
Prigogine Medal 2010: Felix Müller, Germany
Felix Müller studied biology, geography and chemistry at the Universities of Kiel and Regensburg, before completing his Doctoral thesis at the University of Kiel on the topic of the impact of selected environmental chemicals in the soil.
Prigogine Medal 2011: Larissa Brizhik, Ukraine
Larissa studied physics at Kiev State University before completing her PhD at the Bogolyubov Institute. Her current research interests included electro-photon interaction, soliton mechanism for energy storage and the influence of electromagnetic radiation on biological systems amongst others.
Prigogine Medal 2012: Gerald Pollack, USA
Gerald received his PhD in biomedical engineering from the University of Pennsylvania and since then has carried out outstanding research in a wide variety of fields, ranging from biological motion and cell biology to the interaction of biological surfaces with aqueous solutions.
Prigogine Medal 2013: Vladimir Voeikov, Russia
Vladimir is renowned in the field of physical and chemical properties of water and aqueous systems providing for the biological role of water in bioenergetics, in particular, in aerobic respiration, functions of reactive oxygen species in regulation of biological functions and in bioenergetics.
Prigogine Medal 2014: Mae-wan Ho, UK
Mae-Wan Ho, Director and co-founder of the Institute of Science in Society (ISIS), well recognized for her efforts to reclaim science for the public good and to promote social responsibility and ecological sustainability
in science, received the prestigious 2014 Prigogine Medal in recognition for scientific work in the physics of organisms and sustainable systems she pioneered more than 20 years ago.
Prof Ho is the author of several books and Editor of Science in Society, produced by her Institute. She is a prolific author. Two of her books are prominent in explaining the role of biological water in organising living processes. She has been extremely productive with nearly 200 scientific papers, over 600 popular articles and several more books.
Prigogine Medal 2015: Bai-Lian Larry Li, USA
B. Larry Li is Professor of Ecology and Director of three research Centres at the University of California, Riverside, ie the International Centre for Ecology and Sustainability, the International Centre for Arid Land Ecology, and the US
Department of Agriculture – China Joint Research Centre for AgroEcology and Sustainability. Professor Li has a broad inter-disciplinary background and experience in mathematical, statistical and computational modelling applications in ecological studies.
Professor Li is a Fellow of the Institute for Human Ecology, USA; Chair Professor of the Chinese Academy of Science, Honorary Professor of the Russian Academy of Sciences and Fellow of the
American Association for the Advancement of Science among other important recognitions. He currently presides over the Eco-Summit Foundation and is a member of NFS Scientific Panels. He has been the founder and editor of the prestigious International Journal on Ecological Complexity and the Journal of Arid Land. He organised many symposia and courses with other organisations, including the Max-Planck and Santa Fe Institutes.
Prof Li has worked on a wide variety of ecological projects including recent involvement in energetic and thermodynamic ecological systems and restoration ecological patters formations and long-term ecological research in the USA and internationally. He has published more than 200 refereed Journal articles, and numerous conference papers in addition to 30 book chapters and 8 books or edited special issues.
Prigogine Medal 2016: Brian Fath, USA
Brian's interests range from network analysis to ecosystem theory to urban metabolism to systems thinking and environmental philosophy. Dr. Fath has taught courses on ecological networks and modelling in many different locations around the world.
He is a Professor in the Department of Biological Sciences at Towson University (Maryland, USA) and Research Scholar within the Advanced Systems Analysis Program at the International Institute for Applied Systems Analysis (Laxenburg, Austria). His research is in the area of systems ecology and network analysis applied to the sustainability and resilience of socio-ecological systems. His interests range from network analysis to ecosystem theory to urban metabolism to systems thinking and environmental philosophy. Dr. Fath has taught courses on ecological networks and modeling in many different locations around the world. He holds visiting faculty appointments at the School of Environment, Beijing Normal University and at the State Key Laboratory of Urban and Regional Ecology, Chinese Academy of Sciences both in Beijing, China. He was also Fulbright Distinguished Chair at Parthenope University of Naples, Italy.
He has published numerous research papers, reports, and book chapters. He co-authored three books: He is Editor-in-Chief for the journal Ecological Modelling; President of the North American Chapter of International Society for Ecological Modelling and, among other appointments, he is a member and past Chair of Baltimore County Commission in Environmental Quality.