He is the author of a work *De arte catholicae fidei*, published by Pez (*Thesaurus anecdot. noviss.*, I) and later in *PL* 210 under the name of Alan of Lille. M. Grabmann demonstrated that it belongs to N. of A. It is a theological-apologetic work, aiming to demonstrate the truth of the Catholic faith even to non-Christians. Characteristic of it is the geometric method, which begins with definitions (of substance, of cause, etc.), postulates and axioms, to demonstrate the theorems of Catholic doctrine.
BIBL.: M. Grabmann, *Gesch. der schol. Methode*, Freiburg in Br. 1909-11, pp. 459 ff.; Oberweg, II, p. 247; P. Glorieux, *Répertoire des maîtres en théologie de Paris au XIIIe siècle*, I, Paris 1933, no. 107; E. Gilson, *La philosophie au moyen-âge*, 2nd ed., ibid. 1944, pp. 316-18. Sofia Vanni Rovighi