Though opposed to the government of King Louis-Philippe I, he fully accepted the establishment of the French Second Republic in 1848;[4] nevertheless he took no part in politics, but devoted himself to pastoral care.

[4] Affre was passionate in his determination to improve the study of theology in order to form clergy needed in the challenges which the Catholic Church faced at the time.

On 23 June 1848, faced with starvation due to plans by the French government to close the National Workshops it had recently created in order to provide work to the poor, a large segment of the citizenry began rioting, setting up barricades in the streets of Paris.

Seeing the carnage caused among the civilian population by this campaign, Frederic Ozanam, the founder of the Society of St. Vincent de Paul, begged Affre to intervene to stop the bloodshed.

[5] Accordingly, on 25 June, in spite of the warning of Cavaignac, Affre mounted the barricade at the entrance to the Faubourg Saint-Antoine, bearing a green branch as sign of peace, to address both sides.

[9] In 1856, the smallest of the four "Benjamines," four new bells made for Notre-Dame, was named Denise David in honor of Affre and Amédée-David de Pastoret.

He also wrote a guide to studying the Christian faith, Une Introduction philosophique à l'étude du christianisme (Paris, 5th edition, 1846).