Religio Medici (The Religion of a Doctor) by Sir Thomas Browne is a spiritual testament and an early psychological self-portrait. Published in 1643 after an unauthorized version was distributed the previous year, it became a European best-seller which brought its author fame at home and abroad.
Structured upon the Christian virtues of Faith and Hope (part 1) and Charity (part 2), Browne expresses a belief in salvation "by faith alone", the existence of hell, the day of judgement, the resurrection and other tenets of Protestantism.
There is no Church whose every part so squares unto my Conscience; whose Articles, Constitutions, and Customs seem so consonant unto reason, and as it were framed to my particular Devotion, as this whereof I hold my Belief, the Church of England;..... In brief, where the Scripture is silent, the Church is my Text; where that speaks, ’tis but my Comment: where there is a joint silence of both, I borrow not the rules of my Religion from Rome or Geneva, but the dictates of my own reason.
Science and religion
Throughout Religio Medici Browne uses scientific imagery to illustrate religious truths as part of his discussion on the relationship of science to religion, a topic which has lost none of its contemporary relevance.
Browne's latitudinarian Anglicanism meanders into digressions upon alchemy, astrology, hermetic philosophy, and physiognomy. Throughout his life, the Christian mystic held an interest in esotericism, stating in Religio Medici: 
I was born in the planetary hour of Saturn and I think I have a piece of that leaden planet in me.
the severe schools shall never laugh me out of the philosophy of Hermes.
and I hold moreover that there is a Phytognomy, or Physiognomy, not only of men, but of Plants, and Vegetables; and in every one of them, some outward figures which hang as signs or bushes of their inward forms. 
Reception and influence
A rare surviving contemporary review by Guy Patin, a distinguished member of the Parisian medical faculty, 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'
Throughout the seventeenth century Religio Medici spawned numerous imitative titles, including John Dryden's great poem, Religio Laici, but none matched the frank, intimate tone of the original in which Browne shares his thoughts, as well as the idiosyncrasies of his personality with his reader.
Samuel Pepys in his diaries complained that the Religio was cried up to the whole world for its wit and learning.
A translation into German of the Religio was made in 1746 and an early admirer of Browne's spiritual testament was Goethe's one-time associate Lavater
O to write a character of this man!
Thomas de Quincey in his Confessions of an English Opium Eater also 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 musical effects.
In Virginia Woolf's opinion Religio Medici paved the way for all future confessionals, private memoirs and personal writings.
In the twentieth century, the Swiss psychologist Carl Jung used the term Religio Medici several times in his writings.
- Ole Peter Grell, Dr. Andrew Cunningham (1996). Religio medici: medicine and religion in seventeenth-century England. Scolar Press. ISBN 9781859283394
- Ann Thomson (2008). Bodies of Thought : Science, Religion, and the Soul in the Early Enlightenment: Science, Religion, and the Soul in the Early Enlightenment. Oxford University Pressp. p. 66 ISBN 9780191553080
- Claire Preston (2009). Thomas Browne and the Writing of Early Modern Science. Cambridge University Press. ISBN 9780521107792
- C.a. Patrides Selected Works Penguin 1977 R.M Part 1:12
- ibid. Part 2 Section 2
- Bliss, Michael (1999). William Osler: a life in medicine. Oxford, New York: Oxford University Press. p. 45-46 ISBN 978-0-19-512346-3. OCLC 41439631.