As a young man he had written a work on the Mass entitled "De genuina missæ notione", in which the idea of the sacrifice was relegated to the background, and which was put on the Index.
Nevertheless, a number of Catholics were not reassured, and when in 1842 and the following years there was question of appointing Hirscher coadjutor of Freiburg, the historian Hurter and Baron de Rinck, raised a cry of alarm.
The "Schweizerische Kirchenzeitung" and the "Revue Sion" accused Hirscher of being an enemy of Rome and everything Roman, of dreaming of a German national Church, of opposing celibacy, the Breviary, and ecclesiastical discipline with regard to mixed marriages, of preventing the Freiburg theological review from attacking his benefactor Wessenberg, of being the friend of the Baden Liberals.
Two years later, when the Government of Württemberg wanted to have Hirscher appointed coadjutor to the aged Bishop Keller of Rottenburg, Rome refused.
He preferred lay associations to be undenominational, and favoured a synodal organization in which the laity would be represented, and which should be periodically convened by the bishops and presided over by them.
Several of the bishops were aroused, and attention was drawn to the opinions in Hirscher's pamphlets that had been condemned already by Pope Pius VI in his Constitution "Auctorem fidei".
The canonist George Phillips, the future Bishop Fessler, and Fathers Amberger of Ratisbon and Heinrich of Mainz, refuted Hirscher.
In 1862 after collaborating with Ignaz von Döllinger in drawing up the programme of the famous congress of Catholic scientists to be held at Munich, the following year, he quietly withdrew, judging that the time was not ripe for such a meeting.
In 1848 he proposed a motion that the grand duke should be asked to employ "every means to preserve genuine Christianity, active and living, among all classes of society, especially among the young".
In 1850 he asked that the grand duke should attend to the wants of the Church, and that he should grant without delay the establishment of three or four petits séminaires, where future clerics should be trained during the time of their gymnasium studies.
Hirscher was an excellent priest whom many of his contemporaries, according to the testimony of Adam Franz Lennig, venerated as a patriarch, and for whom Johann Baptist Orbin had a real devotion.
What he criticized under the name of Scholasticism in his pamphlet of 1823, on the relations of the Gospels with Scholastic theology, were formulæ of a handbook more impregnated with the philosophy of Wolff than with that of Thomas Aquinas.
Finally, the sometimes too bitter attacks of which he was the object prevented the diffusion of certain of his ideas; but, on the other hand, his zeal as a catechist, his exalted piety, his personal influence, the purity of his intentions, the ardour he displayed in his defence of Vicari, the part he played in the religious awakening in Baden, recognized by the "Historisch-politische BIätter" in 1854, won for Hirscher the gratitude of German Catholics.