This chapter continues the search for the evolutionary leap from animal to human being. First A. N. Leontiev's model of the evolutionary Activity-stages is laid out. As the elegant model both completes the productive sphere and fails to deliver the defining human difference, it is argued that the missing link must be found in the reproductive sphere. Since reproduction of new generations—from birth to gestation to nurture and extended care—is surplus labor by another name, we are led back to the Marxist idea that labor created the human being. How human labor could spring from animal reproductive labor has still to be explained though.