Why It Is Appropriate to Address Someone with a Ph.D. as “Doctor”

Ph.D. stands for “Doctor of Philosophy.” To earn this degree, one must make an original contribution to humanity’s body of knowledge (In ancient Greek, “philosophy” means “lover of wisdom”). It is an extraordinary feat, taking years of dedicated study at graduate school. The course of study culminates in the candidate writing and defending a thesis dissertation, which must be approved by more senior experts in the chosen discipline (history, education, biology, etc.).