 Van Fraassen’s point is that a theory can be empirically adequate, and hence latch on to the observable regularities in nature, without being true. The scientific competition between theories hinges on which theory accurately describes the observable world; it does not hinge on which theory is actually true. Thus, it would not be miraculous for science to arrive at an empirically adequate, scientifically successful, yet false theory. (See the discussion of the Miracle Argument in the entry on  scientific realism  for more on the miracle argument as a consideration in favor of scientific realism.)