such a great influence on Dante Alighieri's Divine Comedy, that Dante's epic poem has been called "the Summa in verse". Even today, both in Western and Eastern Catholic Churches, and the mainstream original Protestant denominations (Anglicanism and Episcopalianism, Lutheranism, Methodism, and Presbyterianism), it is very common for the Summa Theologiae to be a major reference for those seeking ordination to the diaconate or priesthood, or for professed male or female religious life, or for laypersons studying philosophy and theology at the collegiate level. Structure The Summa is structured into: 3 Parts ("Pt."), subdivided into: 614 Questions (; or "QQ"), subdivided into: 3,125 Articles ("Art."). Questions are specific topics of discussion, whereas their corresponding Articles are further-specified facets of the parent question. For example, Part I, Question 2 ("The Existence of God") is divided into three articles: (1) "Whether the existence of God is self-evident?"; (2) "Whether it can be demonstrated that God exists?"; and (3) "Whether God exists?" Additionally, questions on a broader theme are grouped into Treatises, though the category of treatise is reported differently, depending on the source. The Summa three parts have a few other major subdivisions. First Part (; includes 119 QQ, 584 Articles): The existence and nature of God; the creation of the world; angels; and the nature of man. Second Part (includes 303 QQ, 1536 Articles), subdivided into two sub-parts: First part of the Second Part ( or Part I-II; includes 114 QQ, 619 Articles): General principles of morality (including a theory of law). Second part of the Second Part ( or Part II-II; includes 189 QQ, 917 Articles): Morality in particular, including individual virtues and vices. Third Part (Tertia Pars; includes 90 QQ, 549 Articles): The person and work of Christ, who is the way of man to God; and the sacraments. Aquinas left this part unfinished. Supplement (99 QQ, 446 Articles): The third part proper is attended by a posthumous supplement which concludes the third part and the Summa, treating of Christian eschatology, or "the last things". Appendix I (includes 2 QQ, 8 Articles) and Appendix II (includes 1 Q, 2 Articles): Two very small appendices which discuss the subject of purgatory. Article format The method of exposition undertaken in the articles of the Summa is derived from Averroes, to whom Aquinas refers respectfully as "the Commentator". The standard format for articles of the Summa are as follows: A series of objections