In this address, Jensen discusses his views on the effects of heredity and environment on human intelligence, in an attempt to clarify his original statements on this subject. Since his article appeared in the "Harvard Educational Review" in 1969, the term "Jensenism" has accrued a variety of meanings through popular usage (according to Jensen) and his ideas have been attacked on the basis of these accrued meanings. In this article, Jensen restates his original views on the nature-nurture argument, deals with the types of reactions to and criticisms of "Jensenism," heritability, and teachability, with particular reference to heritability in the Negro population, and discusses the educational implications (namely, compensatory education) of his ideas. (SB)