Louis-Claude was born into minor aristocracy in Amboise, in 1743. His mother had died shortly after his birth, but he formed a close relationship with his stepmother, reflected in his great enjoyment of ladies' company and the close positions some held in his groups, even though he never married.

He studied law at his father's request, but finding it unsatisfying south a commission in the army, which, not being involved in war at the time, afforded him a lot of time to read. In 1768, while he was posted to the Regiment in Foix, near Bordeaux, he was introduced to Martines de Pasqually, the founder of an extraordinary variation of the early Scottish Rite, or Rite Ecossaise, called the Order of Elect Priests (or Cohen) or the Universe. What set this Order apart from mainstream Freemasonry at the time was that this Order was based on an extraordinary view of religion expressed in his Treatise of the Reintegration of Beings, and the theurgical or magical practices of his Order. Saint-Martin was enthralled, and soon left his Army position to become Pasqually's permanent secretary.

Pasqually left France in 1782 to take up a legacy in Saint Domingo, and his Order fragmented in his absence. Meanwhile, Saint-Martin had become friends with Jean-Baptiste Willermoz, a businessman and prominent Mason in Lyon. While in his company, at the age of 32 in 1775, be published his first work, Of Errors & Truth. While closely reflecting his former Master's Treatise, it was written as a rebuttal of the Encyclopedists and the philosophers of the Enlightenment who, while rejecting the official Church, were also moving towards atheism in seeking all the answers to Science in man and earth alone, exclusion considerations of Higher Powers. He continued his work through his life, publishing a number of influential books - especially among Freemasons and the thinking classes - throughout his lifetime, under the pseudonym of the Unknown Philosopher. As an aristocrat, he was interned during the early day of the French Revolution, but was soon freed when it was realized his books has been put on the Index by the church. He ended his days as a teacher.

His teachings - and possible initiations - led to the formation of an Order called Martinism which currently has many adherents of his Christian mystical philosophy around the world. However, so little of his actual books and teachings have made it to the English language that it is time the Anglophone world has an opportunity to experience this seminal Teacher's writings first-hand.