The Limitations of Reductionism

In my Case for Christianity series of posts, I started with a discussion of the importance of reductionism.  In the book that I intend to write that outlines my case, this advocacy of reductionist thinking was to be followed by a discussion on the limitations of reductionism.  Among the uneducated, the success of reductionist techniques is used as evidence for nihilism and this demonstrates an ignorance of what science actually tells us.

The Limitations of Reductionism

Now some Christians will have an allergic reaction to using a reductionist approach of this kind in a Christian apologetic.  “Reductionism leads to atheism”, they will say, “and cannot yield trustworthy results when considering whether or not God exists.”  Given the way that some simple-minded, nihilistic atheists misinterpret reductionism, their reluctance is understandable yet misguided.

While it is true that some uneducated atheists will say things like, “All human beings are is a bunch of protons, neutrons and electrons”, this doesn’t mean that reductionism is an unreliable method for discovering truth.  Any serious thinker familiar with the evidence knows that reality itself is not reductionist and that nihilistic statements of this kind are made from an ignorance of the facts of science.  To assure ourselves of this, let us consider some of the ways in which reality does not lend itself to a simplistic reductionist interpretation.

Reductionism and Quantum Mechanics

Powerful indications of the holistic nature of reality come from the study of quantum mechanics.  In the famous Two Slit experiment, for example, the behavior of a single electron is determined by the configuration of the experimental system.  If there are two slits available for an electron fired at a barrier, we see an interference pattern.  If there is only a single slit available, we see no interference.  The implications of this result and other results from quantum mechanics such as quantum entanglement and the Observer Effect are mind-bending and fatal to simplistic reductionist thinking about reality.  If the observer has to be considered a part of a correctly formulated experimental system, then how could the only significant parts of the system be the simplest constituents as required by reductionism?

Thermodynamics and Reductionism

Another indication of the limitations of reductionism is found in the study of thermodynamics.  If you were a simplistic reductionist who never studied holistic thermodynamic systems, you would have no way of knowing that there is no such thing as a perpetual motion machine.  Why not?  Because the laws of thermodynamics are statistical and apply to systems and not to the individual elements of those systems.  How do you measure a statistical properties like entropy without knowledge of the system as a whole?

Emergent Phenomena

Let us examine reductionism with a thought experiment.  Let’s say I tell you I have a system that is by mass 5 parts oxygen, 13 parts Hydrogen, 6 parts carbon and we give you the overall mass, temperature and pressure of the system.  Could you tell us about how this system would behave?  The answer to this question is undeniably no.

Why?  While it is possible to calculate how many carbon atoms, hydrogen atoms, and oxygen atoms are in the system, there is not enough information to say anything meaningful about the system.  Is the system benzene, water and oxygen?  Is it graphite, carbon dioxide and hydrogen gas?  Though the simplest elements of the system are known, the behavior of the system cannot be determined because there are an infinite number of configurations of the system and the properties depend on the exact configuration.  If the only information you have about a system is information about its simplest components, then you really know next to nothing about that system.


As we have seen previously, reductionist methods are very powerful tools when studying complex phenomena.  Without such techniques, human beings would still be describing thunder as the “anger of the Gods” on Mount Olympus.  As we have seen above, however, simplistic statements like “all human beings are is a bunch of atoms”  are entirely ignorant of the scientific facts.  “Reductionists” are correct when they argue that it is necessary to consider how the simplest constituents of a system interact in isolation, but it is also essential to consider holistic systems in order to have a meaningful understanding of complex phenomena.

**As part of the discussion of emergent phenomena, I had originally intended to talk about the difference between the effectiveness of various medicines in in vivo vs in vitro studies.  Many medicines that are promising in the lab fizzle in clinical trials because within the actual body the active compound does not behave in the same way as it does in the test tube.  I was also going to talk about hurricanes and how they “emerge” at a certain system scale and do not occur at smaller scales.  I decided not to because I got lazy, but for those who are interested, these are good topics for further research.

About Robert V

Former atheist currently living in Toronto.
This entry was posted in A Case for Christianity and tagged , . Bookmark the permalink.

One Response to The Limitations of Reductionism

  1. Pingback: Reductionism in History | A Thoughtful Christian

Leave a Reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s