8 Conceptual Conservatism: The Case of Normative Functions

What moves us to theorize about purposes in living things? Why are we concerned to
theorize about normative functions that allegedly belong to parts of plants and animals?
We appear to have the intuition that these things are “supposed to” fulfi ll certain functions.
So when we try to explicate this intuition, what are we up to?
I am not asking why we theorize about functions at all. The question is why we theorize
about the alleged normativity of functional properties. What are we doing when we try to
preserve the intuition that functional traits have the property of “being supposed to”
perform specifi c functional tasks even when, due to physical incapacitation, they cannot
perform those tasks? The theory of systemic functions, fi rst articulated by Robert Cummins
and later developed by Ron Amundson and George Lauder in the context of biology, is a
compelling theory of functions that eschews the imputation of normative properties.^1 The
theory of systemic functions therefore is not the target of my discussion. I have in mind
rather the theory of so-called proper—that is, normative—functions developed by a small
army of theorists over the past thirty years or so.^2 The question, then, is what are these
theorists up to when they try to preserve the admittedly powerful intuition that some
functional traits are supposed to do certain things?
My answer is that the urge to theorize about purposes in nature is a product of the fact
that we are conceptual conservatives regarding the concept “purpose.” One source of our
conservatism is the long, deep roots that this concept has in our intellectual and theological
ancestry. A second source is our own psychology, the cognitive and affective capacities
that cause us to apply the concept “purpose.” We are, by virtue of our cultural history and
our psychological constitution, prone to see or feel purposiveness where none exists, and
the force with which we see and feel living things as purposive convinces us that there is
something important there about which we must theorize. The evident power of this illu-
sion illustrates the retarding effects that conceptual conservatism has on our attempts to
know the world.
The specifi c aim of this chapter is to fl esh out and defend this answer to my opening
question. My larger aim, which extends well beyond this chapter, is to generalize from
the retarding effects of “purpose” and suggest that, with respect to a wide range of similarly

Paul Sheldon Davies