The text translated here is from the Latin text published by Adolf Harnack ‘Altercatio Simonis Iudaei et Theophili Christiani’ in Texte und Untersuchungen vol. I, 3 (1883) pp. 1-136. A copy of the text was also published by J.P. Migne Patrologia Latina 20 (1845) col. 1165-1180, where the author is given as Evagrius.
Read the introduction and translation HERE.