Abstract :
It has been claimed that modern long-standing scientific theories are fertile, in the sense of
having been progressively successfully modified to meet new experimental observations
or theoretical developments in related areas, and that these modifications arise naturally
from each preceding version of the theory. McMullin has advanced this form of fertility
as a vindication of scientific realism, since if the theories did not approximate the real,
the observation would be inexplicable. In response Nolan has denied the existence of
fertility in this sense as an independent virtue. The present paper argues that the rebuttal
is flawed.
