Life is a far-from-equilibrium dynamic process, and it is within this context that basic questions concerning living processes must be addressed. I know of no other process that combines such 'unlikely' complexity with the tendency of the organisation to persist over time. Also, there still remains the problem of reconciling life's dynamic complexity with the laws of thermodynamics. Schrodinger (1979), suggested that life maintains its level of order by utilising the order within its environment and evoked the concept of 'negative entropy.' Also, Prigonine must be mentioned for his work investigating life as a far-from-equilibrium dissipative process.

These researchers (and many others) have helped to introduced a 'dynamic systems' approaches to the question of life. However, dynamic systems are very complex and have not, as yet, provided clear solutions to the problems of life. We still do not know, for example, how the many highly complex and dynamic systems that comprise an organism co-operate to the benefit of them all -- processes which are so highly non-linear, with complex feedback relationships, that they form a class often described as intractable, or indeed, chaotic.

Studies into the nature of these highly dynamic and non-linear processes has revealed that under certain conditions they can give rise to what is described as 'emergent properties'. For example, an ants' nest exhibits macroscopic behaviour, in that it undergoes cyclic periods of activity and dormancy. This behaviour is not explicitly programmed into the individual ants. The behaviour 'emerges' as a result of the complex interactions among them. Thus, it is often claimed that the properties of emergent phenomena cannot be predicted from the properties of the components that comprise the system.

Observations of emergent dynamics in complex systems have led many researchers to argue that the mind itself is an emergent phenomenon. However, there are reasons why this approach may be unsatisfactory. The claim that complex dynamic systems give rise to emergent properties implies that something unprecedented is occurring - a new phenomenon. We may justifiably ask, 'How does an emergent process integrate itself successfully into the many emergent processes that comprise a living organism in such a way as to benefit them all?' I suggest that there must be a common principle or property common to emergent dynamic processes that comprise a living organism.

As has been stated previously, the central question being addressed concerns the robustness of living processes. If there is a common principle associated with living processes, how should we determine what it is? At first, the task may seem paradoxical. The claim that all living processes are examples of a single process would imply that we could isolate any arbitrary part of an organism, large or small, and claim that the principle that allows it to maintain its structure and coherence is the same as for any other arbitrary part, even subdivisions of the part that we have already chosen!

However, there is a branch of chaos theory that lends itself to this type of complex organisation -- scale invariance or fractal organisation. A fractal is a geometric object that displays a self-similar structure on every level of scale. Fractal structures have been discovered in living organisms, a popular example being the fern leaf. When we 'zoom in' to the fern leaf we are surprised to discover at the microscopic level the same structural characteristics that we observe on the macroscopic level. Fractal organisation is often associated with structures, however, there are also examples of fractal processes (Dewey 1997).

If life has a scale-invariant organisation, we may now have a clue as to the prototype of the living process. The smallest working component of living processes is a molecule called an enzyme. An enzyme is an example of what chemists call catalysts. A catalyst is a molecule that mediates a reaction between other molecules (reagents), and emerges from the reaction unchanged.

So, given the theme of robustness, the question is -- 'Is a catalyst (and thus, the processes of catalysis) robust?' The answer to this question is 'Yes'. Consider an enzyme in a liquid medium that contains only those reagents for which the enzyme acts as a catalyst. Because the catalyst emerges from each reaction unchanged, both the catalyst and the process of catalysis persist for as long as the environment does not change. Of course, this is a statistical effect. Molecules may spontaneously change as a result of quantum fluctuations or radiation effects. However, all things being equal, a catalyst will have a good chance of persisting for as long as the environment contains only those molecules for which it acts as a catalyst or which are inert with respect to the enzyme.

Let us now take this idea a stage further. For any specific catalyst, there is a hypothetical environment in which that catalyst will persist because it contains no substances that will react with the catalysts in a way that will destroy it. This hypothetical environment would contain reagents at thermodynamic conditions such that the catalysts would mediate the transition from reagents to products. Such an environment we can term 'The environmental survival space' for that particular catalyst.

The 'environmental survival space' described above is very small. However, if interacting complexes of catalysts could give rise to a macroscopic and non-specific catalyst, then the 'environmental survival space' could be much larger. Let us consider the single cell in these terms. It is known that a cell can withstand considerable variation in its environmental conditions. Also, it has a barrier, the cell membrane, that can keep unwanted substances out. I suggest that the metabolism of the cell constitutes a highly dynamic and non-specific catalyst that is able to mediate a range of transitions in a much larger 'environmental survival space.'

What is suggested is that life started as a result of chemical interactions between catalysts facilitated by their survival potential (see also Stuart Kauffman's 1995 'autocatalytic set theory'). If the complex interactions between these catalysts could give rise to another 'emergent' catalytic phenomenon, then the possibility exists that life evolved as a scale-invariant catalytic process - a fractal catalytic process. Thus:

We commonly think of catalysis as a process which is very much rooted in the chemical world. How we can understand catalysis as a process that can operate at the macroscopic level is discussed in depth later.