 Beyond a circular letter to the English Benedictines about their relations with the Vicar Apostolic of England, none of his writings survive.According to Dom Ralph Weldon, Barlow was looked on as a leading theologian and canonist; and effectively opposed Richard Smith, who claimed leadership of the English Roman Catholics, in becoming Bishop of Chalcedon.On the death of William Bishop, the first Vicar Apostolic of England, Barlow was consulted by the pope as to the best successor, and recommended Smith; but later he differed on the question of the extent of the vicar's jurisdiction.