Dogmatist

noun

1. An arrogantly assertive person.
2. One who expresses or sets forth dogma.
3. One who is dogmatic or maintains a dogma or dogmas; a magisterial teacher; one who asserts positively doctrines or opinions unsupported by argument or evidence.
4. [capitalized] One of a sect of ancient physicians founded by Hippocrates, and named in contradistinction to Empirics and Methodists.
5. One who dogmatizes; one who speaks dogmatically; a bold and arrogant advancer of principles.