Grosseteste was the first medieval writer to break with the ancient tradition of discounting refraction in the rainbow. In another way, however, Grosseteste is firmly bound to his predecessors' rainbows an experimentalist in principle, in practice he strays very little from the Aristotelian tradition of selective observation constrained by geometry. Furthermore, Grosseteste's rainbow theory often appeals to authority, leading historian Bruce Eastwood to remark: "When sources fail, he invents, and the invention is never contradictory to literary sources." (In fairness, Grosseteste made several observations about the rainbow that gainsaid ancient authority.)
What's disgusting about the Dirty Harry movies is that Eastwood plays this angry tension as righteous indignation.
Pauline Kael