It is thanks to Msgr. Gauthier that we owe the foundation of the École sociale populaire which was instrumental to awakening and forming the social engagement of Christians.
He was one of the first promoters of Catholic trade unionism. He became chaplain to the first Catholic union formed in Montreal.
He was delighted when Marie Gérin-Lajoie founded the Institute of the Sisters of Notre-Dame-du-Bon-Conseil, which he canonically established on April 23, 1923, for the formation of people involved in women's social projects and in the direction of such projects.