When a theory explains too much…

When I came to college I was already interested in scientific method. I don’t know where that came from. I was full of young person's bravado about how you could use science to examine and unfold the world's mysteries. This must have come from good physics and math teachers in high school. All you needed was observation, an analytical mind and the scientific method.

In college I learned a little philosophy of science and Karl Popper’s notions of falsification. And all was good. I was confident, comfortable, and a bit self-righteous.

Then two things happened. First, I read Paul Feyerabend’s Against Method, a lively rejection of any simple account of scientific method. Science in Feyerabend’s anarchistic reconstruction was (merely) co-extensive with what scientists did. Attempts to dress that up in some common principles was affectation and preening. I did not want to believe this and yet was convinced. It was the first time I read something that strongly changed my mind. This gave me a new and deep respect for the power of written argument.

Second, I took my first organismal biology course and learned the Darwinian selectionist account of evolution; “random” variation, more offspring than survivors, and heritability (children look like parents) leading to adaptation and increased fitness. In the hands of my professors this explained so much. And so much of what I was curious about. It seemed to neatly account for the distribution and abundance of forms in the living world. Each organism was now the barest tip of a story that wended its way back in time through generations, its lineage side-stepping extinction by being better than others. This theory explained in a way that was different than physics theories had. I loved it. From this perspective I could rationalize so much.

Too much it turned out. I noticed that our ornithology professor seemed to find the mores of the 1950s sexual politics in his birds. That didn't seem right. And once you started spinning stories there seemed to be no easy way to know if you were wrong. This was a theory that when applied with panache explained not just this world but was ready to account for almost any set of traits and behaviors. Every bit of every organism. What started out as profound advantage quickly became a liability. And Popper had already taught me that theories that were not falsifiable had a problem.

These experiences turned me. Both to be interested in constraints (biophysical, developmental, and historical) and to be much more careful about ideas that were too broadly applicable. Universal truths became far less interesting to me than local ones.