The notion of emergence

In the previous pages we have discussed how the increase of molecular complexity may proceed via self-organization, emphasizing, however, that a simple increase of size and/or complexity is not enough - this must he accompanied by the onset of novel properties - up to the point where self-reproduction and eventually life itself arise. In fact, self-organization must be considered in conjunction with corresponding emergent properties. 

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 these 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 . 

For a long time, emergence has been an active field of inquiry in the philosophy of science. As noted by McLaughlin (1992), the work of British emergentism can be dated back to Mill (1872) and Bain (1870) and flourished in the 1920s with the work of Alexander (1920), Morgan (1923), and Broad (1925) and the inquiry continues up to the present (see, Wimsatt, 1972 1976a, b), Kim, 1984 Klee, 1984 Sperry, 1986 O Connor, 1994 Bedau, 1997 Farre and Oksala, 1998 Holland, 1998 Primas, 1998 Schroeder, 1998, and several others). 

The possible relevance of chemistry in the notion of emergence was realized as early as the mid-nineteenth century (Mill, 1872) and in 1923, as quoted by McLaughlin (1992), Broad stated that  

In our times, in addition to chemistry and biology, emergence has been discussed in quite a variety of research fields, such as cybernetics, the theory of 

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Central to the general science of complexity, and to the study of artificial life in particular, is the notion of emergence. Emergence refers to the appearance of higher-level properties and behaviors of a system that - while obviously originating from the collective dynamics of that system s components - cannot be directly deduced from the lower-level properties or behaviors of that system. 

We will come back to the questions of non-linearity and complexity when considering the notion of emergence, in the next chapter. 

The reason a full chapter is devoted to emergence, lies in the fact that the notion of emergence connects chemistry and biology to the philosophy of science, and yet this argument is usually dealt with only in the speciaUzed philosophical hterature, which young scientists usually do not read. 

As will become apparent in a later section, if the notion of emergence is to make sense when considering interdiscourse relations between talk of pure substances, chemical molecules, and quantum mechanical calculations, then it is more a case of backward emergentism. It is the details of molecular structure or the introduction of quantum mechanics that is novel, not the properties of pure substances. In contrast, if one takes "novel" in such a way that the most recent theory is the place from which... 

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