Propaedeutics or propedeutics (from Ancient Greek προπαίδευσις, propaídeusis, "preparatory education") is a historical term for an introductory course into an art or science. The etymology of propedeutics comprises the Latin prefix pro, meaning earlier, rudimentary, or in front of, and the Greek paideutikós, which means "pertaining to teaching". As implied by the etymology, propaedeutics may be defined more particularly as the knowledge necessary before, or for the learning of, a discipline, but not which is sufficient for proficiency. The 1851 Encyclopaedia Americana writes that it is: