Baptismal regeneration is the name given to doctrines held by major Christian denominations which maintain that salvation is intimately linked to the act of baptism, without necessarily holding that salvation is impossible apart from it. Etymologically, the term means "being born again" (regeneration, or rebirth) "through baptism" (baptismal). Etymology concerns the origins and root meanings of words, but these "continually change their meaning, … sometimes moving out of any recognisable contact with their origin … It is nowadays generally agreed that current usage determines meaning." While for Reformed theologian Louis Berkhof, "regeneration" and "new birth" are synonymous, Herbert Lockyer treats the two terms as different in meaning in one publication, but in another states that baptism