Paul King Jewett, 71, senior professor of systematic theology at Fuller Theological Seminary in Pasadena and a religious scholar credited with helping develop Fuller into one of the largest seminaries in the country. Jewett, who held a doctorate in theology from Harvard, was an ordained minister in the Presbyterian Church (U.S.A.) who came to Fuller in 1955. At his death he was working on the second volume of a planned three-volume treatise on systematic theology. Another of his works, "Man as Male and Female" (1975), is held in wide esteem as an early plea for equality among the sexes. He also wrote "The Ordination of Women" (1981). In Pasadena on Tuesday of cancer.