When a patient presents himself to one of you as his physician, a mystery is faced. You accept this fact and attempt to unravel the mystery. No one can boast the ability to set out alone, make correct diagnoses and fathom the nature of all diseases, any more than one can chart the course of a given disease or make of an individual case an average case.
Effective treatment is the aim of all medical practice. Early and accurate diagnosis is imperative if treatment is to be effective. It is the general practitioner to whom the average patient first appeals for help; therefore, the former bears singular responsibility. Many diseases are self-limited; some that otherwise carry a high mortality rate are curable when promptly recognized and adequately treated. To treat diseases without a diagnosis and without a knowledge of their behavior may be no more effective than trying to warm
Neal MP. DIAGNOSTIC DRIFTS, DECEPTIONS AND COMMON MISSES. JAMA. 1951;146(6):537-541. doi:10.1001/jama.1951.03670060013003