4 How Biological, Cultural, and Intended Functions Combine

4.1 An Attractive Classifi cation of Functions

What is the function of coffee machines?

To make coffee, of course!

So a coffee machine that cannot make coffee properly is a malfunctioning coffee
machine.

Exactly!

What makes a coffee machine a coffee machine?

The fact that it has been designed and produced for making coffee.

What is the function of the kidneys?

To fi lter the blood.

So a kidney that cannot fi lter blood properly is a malfunctioning kidney.

Exactly!

What gave kidneys their function?

Nature.

This imaginary dialogue introduces some of the obvious answers one may obtain when
inquiring about the function of a typical artifact or a typical biological item. The answers
concerning the artifact seem easy to justify. We plan and produce objects of various sorts
in order that they do something specifi c. The function of a man-made object is then, it
seems, merely the particular effect for which it has been made.^1 It is more demanding to
justify the answers concerning the biological item. One needs to make sense of the idea
that nature may pick out a particular effect and turn it into a function. As is well known,
one way to do this is by employing the selectionist etiological theory of functions, SEL
for short. This theory, proposed by Millikan, Neander, and others in the 1980s in order to
account for biological functions, identifi es the function of a trait with its selected effect

Françoise Longy