It could mean that our idea of sanctity has become very specialised, and that in some primitive cultures the sacred is a very general idea meaning little more than prohibition. In that sense the universe is divided between things and actions which are subject to restriction and others which are not; among the restrictions some are intended to protect divinity from profanation, and others to protect the profane from the dangerous intrusion of divinity. Sacred rules are thus merely rules hedging divinity off, and uncleanness is the two-way danger of contact with divinity.