How Sinful Is Sin? How Vicious Is Vice?

We defend the guise of the good thesis in a tradition going back to Socrates and Plato, according to which persons act on the basis of what appears to them as good or the least bad or evil act available to them. This seems contrary to moral experience, but we defend the thesis against plausible counter-examples in life as well as fiction. We contend that the thesis makes wrong-doing and vice intelligible, but still wrong, dysfunctional and horrific.
 