Not supported by fact

• Like some reasoning
• Based on theory
• Derived by logic, without observed facts (Latin)
• Based on logic instead of evidence
• Like some justifications
• Based on deduction as opposed to experience
• Existing independent of experience, in logic
• Logician's phrase
• Taken at face value

Wiktionary Word definitions in Wiktionary
adv. (alternative form of a priori English)