Sir Thomas Browne's Religio Medici was in its day a European best-seller which brought its author fame and respect throughout the continent. Because an unauthorized version of Browne's thoughts upon the Christian virtues of Faith, Hope and Charity, were mercilessly distributed and reproduced with added text, the newly-qualified physician found it necessary to publish an authorized version of his spiritual testament and psychological self-portait in 1643. Samuel Pepys in his diaries complained that the Religio was, "cried up to the whole world for its wit and learning", and its unorthodox views placed it swiftly upon the Papal index in 1645.

Although predominately concerning itself with Christian faith, 'The Religion of a Doctor' also meanders into digressions upon alchemy, hermetic philosophy, astrology, and physiognomy. Whilst discussing Biblical scripture the learned doctor reveals a penchant for esoteric learning, for example confessing,

"I have often admired the mystical way of Pythagoras and the secret magicke of numbers";

Browne's latitudinous Protestantism equally allowed him to declare that,

"the severe schools shall never laugh me out of the philosophy of Hermes" .

A rare surviving contemporary review by a distinguished member of the Parisian medical faculty, Gui De Patin (1601/2-72) indicates the considerable impact Religio Medici had upon the intelligentsia abroad.

A new little volume has arrived from Holland entitled Religio Medici written by an Englishman and translated into Latin by some Dutchman. It is a strange and pleasant book, but very delicate and wholly mystical; the author is not lacking in wit and you will see in him quaint and delightful thoughts. There are hardly any books of this sort. If scholars were permitted to write freely we would learn many novel things, never has there been a newspaper to this; in this way the subtlety of the human spirit could be revealed.

A translation into German of the Religio was made in 1746 and in the twentieth century the Swiss psychologist C.G.Jung used the term Religio Medici several times in his writings.. The Religio Medici was 're-discovered' in the early nineteenth century by the English Romantics, in all probability firstly by Charles Lamb who introduced it to Samuel Taylor Coleridge, who exclaimed after reading it, "O to write a character of this man !" Thomas de Quincey in his Confessions of an English opium eater equally praised it stating,
"I do not recollect more than one thing said adequately on the subject of music in all literature. It is a passage in Religio Medici of Sir T. Browne, and though chiefly remarkable for its sublimity, has also a philosophical value, inasmuch as it points to the true theory of music effects".

Though little read nowadays in Virginia Woolf's opinion the Religio paved the way for all future confessionals, private memoirs and personal writings.In the seventeenth century it spawned numerous imitative titles but none matched the frank, intimate tone of the original in which the learned doctor invites the reader to share with him in the labyrinthine mysteries and idiosyncratic views of his personality.