[In Alpbach] I also began suspecting that what counts in a public debate are not arguments but certain ways of presenting one's case. To test the suspicion I intervened in the debates defending absurd views with great assurance. I was consumed by fear -- after all, I was just a student surrounded by bigshots -- but having once attended an acting school I proved the case to my own satisfaction. The difficulties of scientific rationality were made very clear by.
Science in a Free Society, London: Verso, 1978. p.109.
And where arguments do seem to have an effect, this is more often due to their physical repetition than to their semantic content.