In a recent thread the concepts of purpose and function came into debate and discussion regarding the origins and evolution of life. From that thread it is clear that different people have different ideas of how each of those terms is defined, used and whether and how they can be observed.
For the purposes of this thread, I am defining purpose as the reason for which something is done or created or for which something exists. There are several definitions, but I found this definition through Google and find it fits closely with my basic definition. Additionally, I thought it was suitable enough as a launching point for this discussion. From my view purpose is a concept associated with an agent. Humans are agents that create with purpose. Of course, there are other living things that do this too. But these are the only things that I know of for which there is evidence to show purpose.
It is more difficult, as it turns out, to come up with a simple definition for function and many exist depending on the context. There are functions in music and math as well as social events. That these may have some fit to the discussion, I am leaving open. As to a definition for the purpose of this thread, I think the one that applies to engineering is sufficient, but that too can be discussed and debated. To launch this thread, discussion is defined as a specific action that a system can perform.
I do not interpret purpose and function to be equivalent. I do not see function as the necessary result of an agent, though agents often use function to achieve some purpose. Somewhere in all of this, it is quite likely that the thread will turn to the concept of intent. I intend it to and hope that it functions in some way to achieve that purpose.
So from these simple beginnings, I would like to increase my understanding and definition of these two concepts through a, hopefully fruitful, discussion and debate. To explore how they are applied and discover what evidence exists to support claims about either. And enhance my view of the relationship between function and purpose and how they are applied to questions like creation, science, and in particular, the phenomena and theory of evolution.