Herbert Moore Pim (6 June 1883 - 12 May 1950) was born in Belfast into a Quaker family and worked as an insurance employee, poet, occult-fiction writer, political activist and pamphleteer. He changed both political and religious allegiance several times during his life, and his literary career is complicated by pseudonyms - he published The Pessimist and Unknown Immortals under the name A. Newman - and by a good deal of autobiographical invention.

His fiction draws on occultism, religion, reincarnation, spiritual transformation and moral allegory. Taken together, his work is notable for combining occult fiction, religious speculation, political pamphleteering, sexual frankness and self-mythologising.