Archive for January 3rd, 2011

January 3, 2011

Purpose (1) – Introduction

by Neil Rickert

In a recent blog post at BioLogos, Dave Ussery wrote:

I do believe that life’s history is infused with purpose and that this process is God’s process.

I agree with the first part of that.  The second part is why scientists often try to avoid talk about “purpose.”  The problem that science sees in the second part, is that it is an attempt to explain purpose that is not evidence based.  And yet people find “purpose” and other intentional words a very useful part of their vocabulary.

This post is intended to be the first of a series where I discuss “purpose” and similar intentional words, and where I attempt to provide a basis for intentional language that is entirely natural and is consistent with the scientist’s requirement of evidence.  If there are aspects of our use of purpose that are inherently mystical or religious, I won’t be attempting to deal with those.

Science usually attempts to give what we might consider to be mechanistic descriptions of what it is studying.  However, in our non-scientific lives, many of our descriptions are based on purpose, rather than on mechanism.  Take this blog, for example.  A mechanical description would be about the physical events that take place to cause a pattern of illuminated pixels on your screen.  That’s fine if we are interested in the physics of digital displays, but it is not satisfying if we are interested in what the blog is about, in what meaning it is attempting to convey.  To convey those meanings and interests, we need an account that uses our intentional vocabulary, our words that talk of purpose, goal, aim, intention, meaning, etc.

The attitude of many scientists with regard to purpose is well illustrated in a recent post to an internet forum:

Purpose is a human construct implying intent, which is another human construct. Science has nothing to say about purpose and intent. Once you’ve started talking about purpose you’ve left the realm of science.

I am sure that expresses a rather common view.  However, if to talk about purpose is to leave the realm of science, then study areas such as Psychology and Cognitive Science will have to be abandoned or at best to be recognized as being outside the realm of science.  I do no see any reason to exclude those fields from science.

There is an alternative to excluding purpose from science.  And that alternative is to find a natural basis for purpose such as will make purpose itself potentially something that science can study.  And that is the direction that I will be taking in this series of posts.


We use “purpose” and other intentional words in a number of different ways.  A brief discussion is appropriate.

I might say that the purpose of my automobile is to get me to work and then home again.  However, when I use “purpose” in that way, I am not really talking about the automobile having a purpose.  Rather, I am talking about me having a purpose, and using that automobile as part of how I fulfill that purpose.  So when I use “purpose” in that way, it really means the same as “use”, as in “I have a particular use for my automobile.”  We can discount that particular way of using “purpose” as not being about what we ordinarily understand as purpose.

The other extreme would be to limit the word “purpose” to the case where a person has a conscious purpose.  I want to avoid that particular usage, because it is rather difficult to characterize what we mean by “conscious.”  In between, there are many systems that exhibit what we might describe as “apparently purposeful behavior.”  And that is where I wish to target this series of posts.  That kind of behavior can be seen in many biological organisms, including those such as plants that we would never consider to be conscious.  But it is not restricted to biology.  We can describe a thermostatically controlled system as having apparently purposeful behavior.  Because of its relative simplicity, the thermostat is reasonably well understood, so I shall occasionally use it as an example in the series.  Here, and throughout this series, I shall sometimes use “thermostat” as shorthand for “thermostatically controlled system.”