Freethinking/freethinkers
A name which draws on the subtitle of the book, "A book for Free Spirits," this name sets Nietzsche's thoughts against the assumptions of his time. He considers himself free from the limitations of both the theological Christian tradition, and the dominant philosophies of his day. This term also includes senses of transcendence, namely elevating one's self above the cultural assumptions of one's day.
Natural Law
Nietzsche uses this term to criticize it's assumptiveness, arguing that since God doesn't exist, natural law can't either. Natural law is the belief that ethics come from a higher source, like God.
Skepticism
A denial of a system based on its inverifiability. A forerunner to Ayer and the Logical Positivists some fifty years later.
Obscurantism
Used in contrast with Enlightenment to denote a skeptical system of thought that intentionally casts doubts on truths that are not completely evident. Nietzsche attempts to reconstruct obscurantism as a healthy, skeptical force.
Christianity
The belief that Christ was the Jewish messiah and died and was resurrected for the remission of sins. This belief is criticized by Nietzsche who calls into question both the truth of its claims and the honesty of the believers who say they believe it.
The Poet/The Artist
A metanymous representation of someone who creates art to be admired by others. For Nietzsche, this person is also a culture-shaper and a good deal of time is spent discussing what art is and where it comes from if there is no God.