What are the main issues in inherit the wind

Specifically, Cates has violated a town ordinance that forbids the teaching of any theory other than Creationism. This is why he is actually arrested. The issue of free thought is then brought up by Henry Drummond. Drummond contends that this is a constitutional issue and that Bert Cates should have the right to teach the Theory of Evolution. He believes that this is censorship and has no business being regulated by the courts.