Scholastics split dulia: hyperdulia for Mary as Lady and Queen, proper dulia for the other Saints
Mary’s maternity of the Son of God lifts her above other Saints as Lady and Queen.
Hence Schoolmen bisect dulia: hyperdulia for her, proper dulia for the rest.
Latin
III. Caeterum quoniam Beata Virgo, ut Mater filii Dei, ita praestat aliis Sanctis ut juxta doctorum illorum sententiam, dici possit Domina & Regina nostra, quod aliis Sanctis non convenit, nisi admodum imperfecte; ideo Scholastici hanc tertiam speciem, quam vocant Duliam, dividunt in Duliam proprie dictam, & Hyperduliam, hanc tribuentes Beatae Virgini, illam vero caeteris Sanctis.