Matthew Slater

"That is often the job of philosophers, to notice that there are tensions and puzzles right under our nose we didn't notice or we didn't attend to, and to go in and see if we can't resolve the puzzle."

Assistant professor of philosophy

Sometimes the most basic concepts require reflection. Take the idea of biological species, for instance. Even toddlers delight in distinguishing cows from horses from doggies.

"People know what makes a robin different from a chickadee," says Assistant Professor of Philosophy Matthew Slater. "The philosopher asks what exactly are you recognizing." It turns out that defining a species is not as straightforward as it first seems. One common definition, the ability to interbreed and produce fertile offspring, quickly breaks down — when applied to asexual organisms, for example.

The difficulty of defining "species" calls into question the significance of "discoveries" of subdivisions within existing species. In the last few years, for example, genetic studies have suggested that giraffes represent as many as six different species. But what does that mean, if establishing a valid and universal definition of species remains a subject of debate amongst biologists?

"That is often the job of philosophers, to notice that there are tensions and puzzles right under our nose we didn't notice or we didn't attend to, and to go in and see if we can't resolve the puzzle," Slater says.

Slater extends the questions about biological categories to other levels. "Our classification system works at all kinds of levels of granularity," he says. "Say we're trying to figure out something about the human liver - we might look at mouse livers. That only makes sense if 'liver' names a kind of thing that mice have and we have that are relevantly similar."

Just as in the concept of species, the similarity of livers or other organs seems obvious, but developing an exact definition of different tissue types might be messier that it first appears. "The question would be what structure is there to divide the livers from kidneys or from brains," Slater says. "What you are going to encounter, I suspect, is a lot of variability ... The challenge then becomes how much of that variability to overlook in determining whether 'liver' names a natural kind of organ system."

Slater was recently awarded a National Science Foundation Scholar's Award to spend a year exploring these questions, talking with scientists about different levels of biological classification, from microbial ecologies to species and higher taxonomic grouping.

Slater looks forward to teaching in Bucknell's liberal arts environment, where his classes will contain students from majors across campus. "Even if they don't become philosophy majors, what I hope happens is they become philosophers nonetheless, in the sense that they are willing to ask deep and difficult questions and really look carefully at their home subject matter, whatever it happens to be," he says.

Posted Sept. 22, 2009