 He entered the Society of Jesus, 1 July 1611, taught belles-lettres for many years at various colleges in France, philosophy for five years, theology for thirteen years, and became theologian to the General of the Society.In 1647 he published the first part of his work "Apologeticus Fidei" titled "Institutio Theologica de vera Religione" In 1645 the second part, "Demonstratio dogmatum Christianorum", appeared, and in 1646 "Dissertationes theologicae" on the Sacrament of Penance.In his "Avis aux Catholiques", Bagot attacked the new doctrine on grace, directing against it also his "Lettre sur la conformite de S. Augustin".