The Enlightenment, a unique period in the history of Europe, was founded in the scientific and intellectual revolution of the 17th century. Renal anatomy and physiology advanced through the work of men like Eustachio, Malpighi, von Rosenstein and Cotugno, who described both normal and pathologic structures. Despite the earlier discovery of renal tubules and glomeruli, their anatomic and physiologic relationship remained unclear during the 18th century. The definitive explanation would not come until the work of Bowman and Bright in the 19th century. Similarly, the role of renal nerves would not emerge until the 19th century, when Claude Bernard elucidated their role in controlling urine flow in the dog. A key figure was Morgagni (1682-1771), who provided highly precise descriptions of a number of urinary tract anomalies and forms of obstructive nephropathy and developed many insights into renal pathophysiology by pure deductive reasoning. He gave a remarkably accurate description of the basis of reflux nephropathy and recognized that urinary calculi could have many etiologies. Lithotomy was performed as a last resort, and Cheselden reduced the mortality to 17% with a perineal approach; Baseilhac designed a new instrument to facilitate the suprapubic approach. Despite the high quality of men such as Morgagni, physicians had a reputation for quackery and rapacity, and most of their efforts met with little success.