Yes, Ph.D. graduates (Doctorate in Philosophy) are also called doctors since they’ve gathered remarkable knowledge and have mastered a certain field. They’re also called doctors owing to their extraordinary knowledge that can be of great help. For instance, a doctor from a medical field uses their extraordinary knowledge to come up with a treatment that can save the lives of the patients. Similarly, a Ph.D. graduate can always come up with a solution that can make the lives of endless people better than before.