An odd sense of dissonance comes over me as I listen to the eloquent and eminently reasonable arguments presented by Professors Achinstein and Laudan. Nothing similar to either of their remarks would likely be heard today at a history of science meeting, much less at a convention, say, of the Modem Languages Association. Historians would be much more likely to ask what interests were served by the particular rhetorical characters of Whewell's or Brougham's or Mill's or even Young's or Fresnel's arguments. They would be deeply skeptical that arguments per se had anything much to do with the contagious expansion of wave methods during and after the 1830s. In their respective ways, and despite the obvious differences between them, Professors Achinstein and Laudan both feel that argumentation was a central aspect of the historical events involved in the establishrnent of wave optics.