Biology Reference
In-Depth Information
4.
INTRODUCTION OF A NUMBER OF PHILOSOPHICAL
ASPECTS OF SYSTEMS BIOLOGY
4.1. Two types of reductionism
Most biologists use reductionist strategies in some way or another. Often they
are indifferent to the philosophical aspects of their methodologies, theories and
explanations. Quinn highlighted the attitude of most scientists towards reduc-
tionism by paraphrasing Mark Twain's comment on the weather:
“Mark Twain once said about the weather 'everybody talks about it, but nobody
does anything about it'. It seems to me that the inverse applies to reductionism:
everybody does it, but nobody wants to talk about it!”
(Bock & Goode, 1998, p. 218)
The notion of reductionism in connection to biology has attracted the attention of
at least some biologically oriented scientists and of philosophers of science for
several decades (e.g. The Alpbach Symposium in 1968 and the Novartis Foun-
dation Symposium in 1998 (Koestler & Smythies, 1969; Bock & Goode, 1998)).
The term 'reductionism' is not unambiguous; it is used to refer to (i) the
research strategy of trying to understand complex systems by studying their parts
and (ii) the claim that a particular scientific theory has been reduced to another
theory according to a particular paradigm of how theories can be reduced to
each other. Examples of the latter claim are the reduction of thermodynamics
to statistical mechanics and the present efforts to reduce the four interactions
(forces) of physics to a single underlying one. Reductionism in the former sense
is quite distinct from that in the latter. The context will determine which type of
reductionism is being referred to in a particular instance. In both cases though,
the natural world is thought to be somehow stratified in higher and lower lev-
els. Living systems (wholes) are invariably composed of components (parts),
where the parts in their turn can each be considered as wholes themselves that
consist of even smaller parts, and so on (e.g. cells are composed mainly of
macromolecules such as enzymes and enzymes are composed of amino acids).
Entities of higher levels are thought to be composed of entities that populate
lower levels. Although their notions of what constitutes a level differ, most
scientists and philosophers agree that the implementation of some concept of
level or hierarchy is indispensable to understanding the natural world. Given this
basic organization of the world, some have argued that it should be possible to
reduce entire disciplines at higher levels to disciplines at lower levels (e.g. to
reduce biology to chemistry which is then reduced to physics, or to reduce phys-
iology to biochemistry or to reduce Mendelian genetics to molecular genetics).
Eventually this should lead to a 'theory of everything' (Nagel, 1979). Theory
reduction would also result in the growth of scientific knowledge. The discussion
