The Pathfinder Society is a globe-spanning organization based out of Absalom, the world's largest city. The membership consists primarily of Pathfinders, adventurers who travel throughout Golarion, usually inconspicuously, and explore, delve, and otherwise experience the lesser-seen parts of the world. They send journals back to their venture-captain, who also assigns them new missions and suggests new places to explore. The most exciting and illuminating of these journals are compiled in the Pathfinder Chronicles, an ongoing series of books which collect the history and mystery of Golarion for their membership.
The Pathfinder Society is willing to accept members of all backgrounds, creeds and morals. Any applicant who does well enough overall on the initial tests is allowed to take the oath and become an initiate. Training is overseen by three deans, the Master of Swords, the Master of Spells and the Master of Lore. The final test, Confirmation, is taken after 3 years as an initiate (although ambitious or gifted initiates may persuade the deans to allow them to take the test earlier). The test is effectively the initiate’s first mission; those who pass become Pathfinders and those who fail are discharged from the Society (but often remain on good terms with it afterwards)
Members of the Society are loosely affiliated adventurers, who are not required to interact. However, they are forbidden direct conflict against each other, but this doesn't stop the more unscrupulous from leading rival parties into dangerous situations and dead ends. Most are issued a Wayfinder, which is a type of magical compass, and taught to recognize the signs indicating a lodge. Other than that they are largely free to be and do what they please. This allows for a very varied membership, with a Chelaxian devil-binder and a Garundi rogue easily finding themselves sharing a night in the same lodge in the far north of Avistan.