in 1528. 1 However, internal medicine as a medical specialty emerged many years later. It was preceded by the development of nosology, a branch of medical science that deals with the classification of diseases. The most important founder of nosology was a great English physician, Thomas Sydenham (1624-1689). He described a variety of distinct diseases based on symptoms, signs, and other clinical observations. Later, a French physician François B. de Sauvages de Lacroix (1706-1767) published the first classification of diseases based on symptomatology. These findings were expanded by descriptions of new disorders based on careful observations. In 1761 in Vienna, Leopold Auenburgger (1772-1809) introduced percussion, and in 1816 in France, René T.H. Laënnec (1781-1826) invented the stethoscope and introduced auscultation to medical "There are two ways of spreading light: to be the candle or the mirror that reflects it."