Luisi: The Emergence of Life: Chapter 6: The Notion of Emergence

Luisi, P. L. (2006). The emergence of life : from chemical origins to synthetic biology. Cambridge: Cambridge University Press.

Chapter 6: The Notion of Emergence

This book attempts to make a bridge from chemistry to biology, and deploys the concept of emergence and self-organizing systems in that process.

“The term ‘emergence’ describes the onset of novel properties that arise when a higher level of complexity is formed from components of lower complexity, where those properties are not present. This is often summarized in the popular assertion that the ‘whole is more than the sum of the parts’, and/or with the vague term ‘holism’” (112).

Luisi then distinguishes between two forms of discussions relating to emergence: the ontic and the epistemological (113). He claims that his argument will deal with the epistemological argument, as it is more practical and applicable.

Luisi also approaches the concept of complexity theory. He also claims that he will not pursue this in much depth but does provide a simple definition: “…a complex system is seen as a hierarchic system, i.e., a system composed of subsystems, which in turn have their own subsystems, and so on” (113).

He then looks at the relationship between emergence and reductionism. Typically, “reductionism and emergence are presented as two opposite fronts: whereas emergence deals with the onset of novel properties, which are not present in the basic components, and as such has an upwards direction, reductionism generally looks down from a certain level of complexity claiming to explain each level on the basis of the lower ones” (116). “…the main point of opposition between emergence and reductionism concerns the problem of properties. There is nothing wrong, in principle, with reductionism when it stops at the level of structure: we can all agree that water consists of hydrogen and oxygen. The problem with reductionism is with the claim that the properties of water can be reduced to the properties of hydrogen and oxygen, and those to the properties of more elementary particles” (117).

Luisi then moves onto prediction: is it possible to foresee the emergence of water from hydrogen and oxygen either a priori or a posteriori? Some see the relationship between emergent properties and original properties as being unexplainable. This, Luisi calls either strong emergence or radical emergence (118). Weak emergence, on the other hand, “…the relationship between the whole and the parts may not be established because of technical difficulties, such as the lack of computational power or insufficient progress of our skills” (118). Some are critical of strong emergence because it seems to associate “magical” powers in the realm of causation between lower and upper levels of organization. Luisi chimes in: “Personally, I believe that the discrimination between a matter of principle (strong emergence), and a matter of practical difficulty (weak emergence), is not always possible—and perhaps it does not always make sense” (118). “…weak emergence si not distinguishable from strong emergence” (118-9). We can accept the premise of strong emergence and avoid the necessary reference to mysterious causality, if we address it in terms of our limited capabilities.

The discussion then moves to downward causation, which is seen as being the counterpart of emergence. “It is generally accepted that the development of emergent properties, which is an upward (or bottom-up) causality, is attended by a downward—or top-down—causality stream” (119). Some associate this with cyclical causality.

Non-linear systems of development are explored. Prigogine is said to present a system of development referred to as dissipative structures. These structures are understood as, “…an open system that is in itself far from equilibrium, maintaining, however, a form of stability…In more complex systems, depending on the initial conditions and fluctuations of the energy flow, the system in its dynamic behavior may encounter a point of instability—the bifurcation point—at which it can branch off with the emergence of new forms of structure and properties” (120).

In conclusion: “The reason why this [non-predictability] is important lies win the fact that novel, unpredicted properties can arise from the constitution of complexity. In other words, the fact that we cannot foresee novel emergent properties also means…that there might be a vast arsenal of unforeseeable properties that may arise from the intelligent or serendipitous assemblage of components” (125).

“We have looked previously at a rose, and claimed that one would learn nothing about a rose by saying that it is composed solely of atoms and molecules. A better approach to the essence of the rose, would be to describe at least the various levels of hierarchic structural complexity and the corresponding emergent properties—up to the various cells and cell organelles, up to the different tissues; and then add possibility the history of biological evolution. This is certainly a more complete view of a rose. It is a departure from the simplistic reductionistic approach to see all in terms of atoms—but is it enough to catch the essence of a rose? (126).

“Most of the cognitive scientists mentioned above would add that what is still missing is the ‘ovswerver0—the one who really gives meaning to the rose in terms of history, literature, poetry, …Obviously the notion of a rose is different depending on whether the observer is a Western educated in romantic literature or a Eskimo who has never seen a rose. Here is where the notion of emergence may become co-emergence between the object and the observer throughout his/her consciousness” (127).