prax•is

– noun
1. practice, as distinguished from theory; application or use, as of knowledge or skills.
2. convention, habit, or custom.
3. a set of examples for practice.

par•a•dox

– noun
1. a statement or proposition that seems self-contradictory or absurd but in reality expresses a possible truth.
2. a self-contradictory and false proposition.
3. any person, thing, or situation exhibiting an apparently contradictory nature.
4. an opinion or statement contrary to commonly accepted opinion.