If anyone declares to you that he has actual proof, from his own experience, of something... even though he be considered a man of great authority, truthfulness, earnest words, and morality, yet... you should hesitate.
The natural course of the human mind is certainly from credulity to skepticism.
Thomas Jefferson (1732-1826)
Our pathology professor's favorite words—"How do you know that?"—caused each of his students to feel simultaneous fear and anger. Why was it necessary for him to question every single answer that we, serious and earnest students, gave in that second-year seminar. Much later, we recognized the important lesson learned in that classroom: maintain a skeptical attitude toward apparently straightforward answers to seemingly simple questions.
Skepticism is a philosophical state of mind essential to the scientific method and to the modern practice of medicine. Ironically and not rarely, skepticism in medical education is often in jeopardy—a victim of authoritative
ALPERT JS, COLES R. Loss of Skepticism in Medical Education. Arch Intern Med. 1989;149(12):2637–2638. doi:10.1001/archinte.1989.00390120009002