When folk theory meets scientific theory?
All of us ordinary folks, even those with little or no technical expertise, have theories. These theories are the way that we try to comprehend our world. Some are explicit and some implicit. Cognitive scientists call these folk theories.
In the West and most likely in all cultures there is a common world view that there is a single correct taxonomy (classification system, taxonomies divide things into kinds) of natural things. These classifications are very important aspects of how human beings make sense of experience. “People have many ways of making sense of things—and taxonomies of all sorts abound. Yet the idea that there is a single right taxonomy of natural things is remarkable persistent.”
It is natural for humans to seek knowledge. In the “Metaphysics” Aristotle wrote “All men by nature desire to know”.
The attempt to seek knowledge presupposes that the world unfolds in a systematic pattern and that we can gain knowledge of that unfolding. Cognitive science identifies several ideas that seem to come naturally to us and labels such ideas as “Folk Theories”.
The Folk Theory of the Intelligibility of the World
The world makes systematic sense, and we can gain knowledge of it.
The Folk Theory of General Kinds
Every particular thing is a kind of thing.
The Folk Theory of Essences
Every entity has an “essence” or “nature,” that is, a collection of properties that makes it the kind of thing it is and that is the causal source of its natural behavior.
The consequences of the two theories:
The Foundational Assumption of Metaphysics
Kinds exist and are defined by essences.
Since scientific theories start with presuppositions they must rely on these folk theories for these presuppositions. Steven Gould provides us with an interesting example of this matter in his What, If Anything, Is a Zebra?.
There are two types of biologists, cladists and pheneticists: “The pheneticists look at overall similarity in form, function, and biological role, while the cladists are primarily concerned with branching order…Ideally, overall similarity ought to converge with evolutionary branching order and yield the same taxonomy.”
These two different modes of classification yield two categories of Zebras.
The details are difficult to follow but the general point is clear. There are at least two kinds of categorizations for Zebra, they should converge but they do not. We have here an example of the rare case when folk theory clashes with the scientific theory.
“A folk theory defines common sense itself…Biology has conflicting taxonomic models that reflect different aspect of reality. The folk theory that there can be only one correct taxonomy of living things seems to be at least partly behind the conflict between the pheneticists, the cladists, and the evolutionary taxonomists.”
Quotes from Women, Fire, and Dangerous Things: What Categories Reveal about the Mind by George Lakoff