diagnostician

noun

1. A person who diagnoses, especially a medical doctor.

   “Dr Smith was many things — a mentor, a friend, a helpful colleague — but his highest calling may have been as a diagnostician, in which role he undoubtedly saved lives by breaking a logjam in many a challenging differential diagnosis.”

   “Dr. Robert Leroy Hutton, a retired specialist in internal medicine and a well‐known diagnostician, died yesterday here.”

   “"More and more, the shrewdest thinkers and artists are precocious archeologists of ... ruins-in-the-making, indignant or stoical diagnosticians of defeat, enigmatic choreographers of the complex spiritual movements useful for individual survival in an era or permanent apocalypse."”