nihilism — total rejection of established laws and institutions.
disbelief — the inability or refusal to believe or to accept something as true.
doubt — to be uncertain about; consider questionable or unlikely; hesitate to believe.
freethinking — a person who forms opinions on the basis of reason, independent of authority or tradition, especially a person whose religious opinions differ from established belief.
heresy — opinion or doctrine at variance with the orthodox or accepted doctrine, especially of a church or religious system.