An Examination of Reductionism

Reductionist views have sometimes been used to write off religious truth (see Richard Dawkins and E.O.Wilson against the possibility of the truth of religion). But not all reductionism is prejudicial to the science-religion debate. Indeed, a form of reductionism is intrinsic to all scientific explanation. Arthur Peacocke writes:

The breaking-down of unintelligible, complex wholes into their component units, the determination of the structures of those pieces and what functions they can perform, and then the fitting of them together as best one can, hypothetically at least, in order to see how they function together in a complex whole, are such common ploys in experimental science that most practising scientists would consider it scarcely worth remarking upon.

Again, science has made great progress through assuming that for experimental purposes living things can be described in terms of atoms and molecules - science need consider no extra fundamental ingredient that makes them living, contrary to the thinking known as vitalism. However, this very basic physicalist assumption is of strictly limited importance. All human beings are made of the same sorts of atoms, indeed the same sorts of chemicals. We do consist of ‘nothing but’ these constituents in the restricted sense that if those chemicals were taken away there would be nothing left. Yet there is clearly more to be said about different human beings than that.

When Francis Crick proclaimed that ‘The ultimate aim of the modern movement in biology is in fact to explain all biology in terms of physics and chemistry’he was seeking to replace one set of scientific descriptions by a more fundamental set. [This is ‘bottom-up’ thinking, which views ‘higher-level’ descriptions as special cases of more basic science. See the EPR Paradox to note that ‘bottom-up’ thinking runs into limitations at the smallest level of things, in quantum theory, but this does not take away its attractiveness in other sciences.]

Three questions may be asked to discover whether Crick’s project has succeeded:

1. do the laws of physics and chemistry apply to the atoms and molecules of living things?
2. are the interactions of atoms and molecules according to physics and chemistry sufficient to account for biological phenomena, or are other kinds of interaction needed?
3. can biological theories be deduced logically from the theories of physics and chemistry?

The answer to the first two is yes, but to the third no. Although biology involves the same matter, and the same forces, as physics and chemistry, new levels of description are needed to do justice to biological systems. So the reduction has not succeeded.

Click on the concept of emergence to explore what needs to be combined with reductionism in order to understand the relation between different sciences.

Or click on the particular case of genetic reductionism to examine some scientific and ethical concerns which it raises.

Or see cross-explanatory reductionism to understand reductionist claims at their most ambitious in respect of religion.

Email link | Feedback | Contributed by: Dr. Christopher Southgate
Source: God, Humanity and the Cosmos  (T&T Clark, 1999)