By the way, in this respect my friend Thomas Kuhn has a lot to answer for. He distances himself from the postmoderns and the social constructivists, but he is endlessly quoted by them. He distances himself in saying that there is a place for evidence and reason in the scientific process—good to hear—but he attacks the idea that we are moving toward objective truth. As far as I can tell from one of his recent articles, his reason for rejecting the idea that science moves toward objective truth is that he and other philosophers have not succeeded in defining truth—and he cannot say what truth would be. This seems a bit like saying that because farmers cannot define cows or the difference between cows and, say, buffaloes, one should doubt the objective existence of cows. I would argue that it’s not the job of farmers to define cows; that’s the job of zoologists. Likewise, it’s not the job of physicists or other scientists to define truth; that’s the job of philosophers. If they haven’t done that job, too bad for them. But just as the farmer generally knows cows when he sees them, we scientists usually know truth when we see it.