Gymnosophy was originally the doctrines of a sect of philosophers who practiced nudity, asceticism and meditation. In the early 20th century, the term was appropriated by several groups to denote a broad philosophy that included as a central thought that the nude human body is a natural condition and should be accepted widely for the betterment of society. This philosophy is related closely, and often interchangeably, with nudism and naturism. They are similar to Jains to some extent,and are recorded to be preaching in ancient Greece.
The biochemist and historian Joseph Needham was known to practice gymnosophy.