CRITERIA OF SYSTEMS THINKING

Fritjof Capra

In science, the framework of systems theory—especially as eloped over the past two decades—seems to be the ideal framework to express the emerging ecological paradigm. This article addresses the question: what is systems thinking—and more generally, holistic or ecological thinking—in modern science? The author identifies three key aspects of systems thinking that are characteristic in all the sciences. In presenting these aspects, the transition from the old to the new paradigm for each aspect is emphasized.

Keywords: philosophy of science; systems theory; paradigm shift

The first aspect of systems thinking concerns the relationship between the part and the whole. In the mechanistic, classical scientific paradigm it was believed that in any complex system the dynamics of the whole could he understood front the properties of the parts. Once you knew the parts, i.e., their fundamental properties and the mechanisms through which they interacted, you could derive, at least in principle, the dynamics of the whole. Therefore, the rule was: in order to understand any complex system, you break it up into its pieces. The pieces cannot be explained any further, except by splitting them into smaller pieces, but as far as you want to go in this procedure, you will at sonic stage end up with fundamental building blocks—elements, substances, particles, etc— with properties that you can no longer explain From these fundamental building blocks with their fundamental laws of interaction you would then build up the larger whole and try to explain its dynamics in terms of the properties of its parts. This started with Democritus in ancient Greece and was the procedure formalized by Descartes and Newton, and has been the accepted scientific view until the 20th century.

In the new paradigm, the relationship between the part arid the whole is just the opposite. We believe that the properties of the parts can only be understood through the dynamics of the whole, The whole is primary, and once you understand the dynamics of the whole, you can then derive, at least in principle, the properties and interactions of the parts. This reversal of the relationship between the part and the whole occurred in science first in physics during the first three decades of the century, when quantum theory was developed. In those years, physicists found to their great amazement that they could no longer use the notion of a part—such as an atom, or a particle—in the classical sense. Parts could no longer be well defined. They would show different properties, depending on the experimental context, appearing, for example, sometimes as particles and at other times, as waves.

Gradually, physicists began to realize that nature, at the atomic level, does not appear as a mechanical universe composed of fundamental building blocks but rather as a network of relations, and that, ultimately, there are no parts at all in this interconnected web. Whatever we call a part is merely a pattern that has some stability and therefore captures our attention. Werner Heisenberg, one of the founders of quantum theory, was so impressed by the new relationship between the part and the whole that he used it as the title for his autobiography Der Teil und das Ganze.

From structure to process

The second characteristic aspect of systems thinking concerns a shift from thinking in terms of structure to thinking in terms of process. Systems thinking is process thinking. In the old paradigm, it was thought that there were fundamental structures, and then there were forces and mechanisms through which these interacted, which gave rise to processes. In the new paradigm, we think that process is primary, that every structure we observe is a manifestation of an underlying process. The shift from thinking in terms of structure to thinking in terms of process is especially important when dealing with living systems. Accordingly, Ilya Prigogine, one of the leading contributors to the theory of self­organizing systems (‘dissipative structures’), entitled his basic textbook From Being to Becoming.

The third aspect is maybe the most profound of all three and the most difficult to get used to for scientists. It concerns the metaphor of knowledge as a building, which has been used in science and philosophy for thousands of years. Scientists speak about fundamental laws, referring to the fundament, i.e. the basis of the building of knowledge. Knowledge has to be built of sound and firm foundations; there are basic building blocks of matter; there are fundamental laws, fundamental equations, fundamental constants, fundamental principles. All this refers to the building of knowledge, for which we also use the German expression ‘Gedankengebäude’ (building of ideas). So, the metaphor of knowledge as a building with solid foundations has been used throughout Western science and philosophy for thousands of years.

In science, the foundations of knowledge were shattered, or at least were shifting, several times, and scientists often commented on that fact. Whenever major scientific revolutions were occurring it was felt that the foundations of science were moving. Thus Descartes wrote in his celebrated Discourse on Method about the sciences of his time: “I considered that nothing solid could he built on such shifting foundations”. Descartes then set out to build a new science on firm foundations, but 300 years later, Einstein, in his autobiography, wrote the following comment on the development of quantum theory:

It was as if the ground had been pulled out from under one, with no firm foundation to be seen anywhere, upon which one could have built.

So again and again, throughout the history of science, there was a feeling that the foundations of knowledge were shifting, or even that they were crumbling. In the present time, the paradigm shift which is happening now, again evokes such a feeling, but this time it may be the last time; not because there won’t be any more progress or any more changes, but because there won’t be any foundations in the future. We may not see it necessary in a future science to build our knowledge on firm foundations, and we may replace the metaphor of the building by the metaphor of the network. Just as we see reality around us as a network of relationships, our descriptions, too—our concepts, models, and theories—will form an interconnected network representing the observed phenomena. In such a network, there won’t be anything primary and secondary, and there will not be any foundations.

This metaphor of knowledge as a network with no firm foundation is something that is extremely uncomfortable for scientists. In physics it was stated explicitly for the first time 25 years ago in the so-called bootstrap theory of particles, formulated by Geoffrey Chew. According to the bootstrap theory, nature cannot be reduced to any fundamental entities, like fundamental building blocks of matter, but has to be understood entirely through self-consistency. Things exist by virtue of their mutually consistent relationships, and all of physics has to follow uniquely from the requirement that its components be consistent with one another and with themselves.

Over the past 25 years, Chew has been using the bootstrap approach, together with his collaborators, to develop a comprehensive theory of subatomic particles, together with a more general philosophy of nature. This bootstrap philosophy not only abandons the idea of fundamental building blocks of matter, but accepts no fundamental entities whatsoever—no fundamental constants, laws, or equations. The material universe is seen as a dynamic web of interrelated events. None of the properties of any part of this web is funda­mental; they all follow from the properties of the other parts, and the overall consistency of their interrelations determines the structure of the entire web.

The fact that the bootstrap philosophy does not accept any fundamental entities makes it, in my opinion, one of the most profound systems of Western thought. At the same time, it is so foreign to our traditional scientific ways of thinking that it is pursued only by a small minority of physicists.

Role of approximation

The three aspects of systems thinking in science which I have presented are all interdependent. Nature is seen as an interconnected, dynamic network of relationships, in which any ‘parts’ are merely relatively stable patterns, and natural phenomena are described in terms of a corresponding network of concepts, in which no part is more fundamental than any other part.

This new approach to science immediately raises an important question. If everything is connected to everything else, how can you ever hope to understand anything? Since all natural phenomena are ultimately interconnected, in order to explain any one of them we need to understand all the others which is obviously impossible. What makes it possible to turn the web philosophy, or network thinking, into a scientific theory is the fact that there is such a thing as approximate knowledge. This insight is crucial to all of modern science. If one is satisfied with an approximate understanding of nature, one can describe selected groups of phenomena in this way, neglecting other phenomena which are less relevant. Thus one can explain many phenomena in terms of a few, and consequently understand different aspects of nature in an approximate way without having to understand everything at once.

Scientific theories, then, are approximate descriptions of natural phenomena. They can never provide any complete and definitive understanding. To put it bluntly, scientists do not deal with truth; they deal with limited and approximate descriptions of reality.