A selectionist explanation for the success and failures of science

I argue that van Fraassen's selectionist explanation for the success of science is superior to the realists' explanation. Whereas realists argue that our current theories are successful because they accurately reflect the structure of the world, the selectionist claims that our current theories are successful because unsuccessful theories have been eliminated. I argue that, unlike the explanation proposed by the realist, the selectionist explanation can also account for the failures of once successful theories and the fact that sometimes two competing theories are both equally successful.