Desi Tamasha

Amartya Sen repeatedly uses the word "heterodox" in "The Argumentative Indian". It stumped me for a while until I looked it up in the dictionary. I still can't understand why he doesn't say "unorthodox". Now Greg Mankiw's gotten into the act also.

Google comes up with 4.5M hits for unorthodox vs about 780K hits for heterodox. Wikipedia baffles with this one: "The noun heterodoxy is synonymous with unorthodoxy and heresy, while the adjective heterodox is synonymous with dissident and heretical."

I'd never use heterodox - I honestly don't think I need it. If I want to say unorthodox, I'll say unorthodox. If I want to say heretical, I'll say heretical.
Link