Osborne has written over a dozen published works focused on the intersection of Western esotericism with Christian orthodoxy. He has examined the alchemical nature of William Blake's art; and theoretical connections between purported haunting and time-slip phenomena. His book Brazen Serpent: Chaos and Order analysed occult concepts in the biblical Nehushtan myth and the 23 enigmaOsborne is best known for his collaboration with Rose Circle Books in the publication of English language editions of eighteenth-century manuscripts derived from the Order of Knight-Masons Elect Priests of the Universe. These include the Treatise on the Reintegration of Beings of Martinez de Pasqually; The de Grainville Manuscripts (otherwise known as the Manuscript of Algiers); and the treatise of the Abbé Fournié, What We Have Been, What We Are, And What We Will Become.