FR. H. NOLDEN, S.J., FR. A. SCHMIT, S.J. — Summa theologiae moralis (Vol. III de Sacramentis), Book 2 Quaestio prima, 1921
Baptism of spirit (flaminis) is perfect charity or contrition, in which the desire in fact to receive the sacrament of Baptism is included; perfect charity and perfect contrition, however, have the power to confer sanctifying grace.