Hull presents philosophical insight on evolution theory

BY JADE BOYD
Rice News Staff

In a thought-provoking Scientia lecture Nov. 19, noted biologist and philosopher David Hull put forward a compelling philosophical argument about the scientific validity of evolutionary theory that challenged some basic notions of humanity.

Hull delivered this fall’s Bochner Lecture, sponsored by Scientia, an institute of Rice University faculty founded in 1981 by the mathematician and historian of science Salomon Bochner. Scientia provides an opportunity for scholarly discussion across disciplinary boundaries; its members and fellows come from a wide range of academic disciplines.

Hull, emeritus professor of philosophy at Northwestern University, once simultaneously chaired departments of biology and philosophy. He has written extensively on both evolutionary theory and the philosophy of science.

Scientia’s theme this year is evolution, and Hull’s lecture focused on the scientific validity of Darwin’s theory of selection, which has been a hotly debated topic since the theory was first published in 1859.

In approaching the question from the philosophical perspective, Hull reasoned that evolutionary theory is valid, but is often misconstrued due to an error in metaphysics.
”If you went to another planet and saw little creatures, what, if anything, would you know about them?” Hull asked. ”You would know that they evolved. They might not have DNA, but they were created by a process of selection. That’s all you would know.”

Hull said the problem with analyzing the scientific validity of evolution is that most people fail to correctly identify ”species” and ”individuals” philosophically.

To start, Hull explained that the quest for scientific knowledge centers upon the discovery of universal laws of nature. Such laws never change, regardless of time or place. For example, an atom of gold will always have 79 protons in its nucleus, regardless of whether the individual atoms are on Earth or on the opposite side of the galaxy. In this example, all atoms with an atomic number 79 fall within the group, or ”kind,” called gold. Any individual atom that meets the definition is a member of the kind called gold. Unlike a kind, which is a category, an individual is a discrete unit that has a beginning and an end.

Hull argues that biological species have all the characteristics of individuals and none of the characteristics of kinds. Therefore, there are no universal laws of nature that apply to homo sapiens or any other taxonomic category such as phylum, order, family, genus and species.

”There are still plenty of laws in ecology and biology, just not those related to taxa,” said Hull. An example would be the effects of panmixia, or random breeding, on species — but only to species in general, not to any particular species.

”There is no science of aardvarkology,” Hull said, ”but half the courses taught at universities deal with only one species.

”To the extent that anthropologists limit themselves to the study of one species, they will never come up with any universal laws,” he said. ”They’ll come up with a lot of good descriptions, and descriptions are very important, but they’re not laws of nature.”