The Lutheran-Anglican worship principle that public worship may include whatever Scripture does not specifically forbid, with substantial latitude for traditional and culturally-appropriate forms. The principle is distinguished from the Reformed-confessional regulative principle (which requires positive scriptural command for worship elements). The substantive theological grounds for the normative principle: (1) the freedom of Christian conscience permits substantive latitude in worship-form questions where Scripture is not explicit; (2) the universal church's substantive accumulated wisdom in liturgical-worship forms provides substantive guidance where Scripture is not explicit; (3) the substantive incarnational principle (worship is embodied in culture and history) requires substantial latitude for substantive cultural-historical embodiment. Historic Lutheran and Anglican traditions retained many medieval-Catholic worship elements on the normative principle: substantial liturgical structure (Lutheran Lutheran Mass; Anglican Book of Common Prayer); clerical vestments; substantial musical traditions (Lutheran chorale tradition; Anglican choral tradition); substantial church-architectural and decorative-art traditions. The Reformed-confessional rejection of the normative principle holds that it substantively under-regulates worship and permits substantial unauthorized additions; the Reformed-confessional regulative principle (Westminster XXI.1) requires positive scriptural command. The patriarchal-Reformed reader holds the substantive Reformed regulative principle while engaging the Lutheran-Anglican normative principle with appropriate care: the substantive question is what constitutes proper scriptural warrant for worship elements and how much latitude is permitted in their application.