The second and third principles of the Augustinian system are likewise false. If delectation is only one motive among many, its varying intensity cannot be the standard of our conduct; and still less can it be said that the will is morally compelled in each instance to obey the relatively stronger as against the weaker delectation; for any necessitation that does not depend on the free will excludes the _libertas a coactione_, but not that _libertas a necessitate_ which constitutes the notion of liberty. There can be no freedom of the will unless the will is able to resist delectation at all times. Consequently, the fourth principle of the Augustinians, by which they pretend to uphold free-will, is also false.(758) READINGS:—The literature on the different systems of grace is enormous. We can mention only a few of the leading works. On the Thomist side: *Bañez, O. P., _Comment. in S. Theol. S. Thom._, Salamanca 1584 sqq.—*Alvarez, O. P., _De Auxiliis Gratiae et Humani Arbitrii Viribus_, Rome 1610.—IDEM, _Responsionum Libri Quatuor_, Louvain 1622.—Ledesma, O. P., _De Divinae Gratiae Auxiliis_, Salamanca 1611.—*Gonet, O. P., _Clypeus Theologiae Thomisticae_, 16 vols., Bordeaux 1659-69.—Contenson, O. P., _Theologia Mentis et Cordis_, Lyons 1673.—De Lemos, O. P., _Panoplia Divinae Gratiae_, 4 vols., Liège 1676.—Goudin, O. P., _De Scientia et Voluntate Dei_, new ed., Louvain 1874.—*Gotti, O. P., _Theologia Scholastico-Dogmatica iuxta Mentem __ Divi Thomae_, Venice 1750.—Gazzaniga, O. P., _Theologia Dogmatica in Systema Redacta_, 2 vols., Vienne 1776.—*Billuart, _De Gratia_, diss. 5 (ed. Lequette, t. III, pp. 123 sqq.).—IDEM, _Le Thomisme Triomphant_, Paris 1725.—*Fr. G. Feldner, O. P., _Die Lehre des hl. Thomas über die Willensfreiheit_, Prague 1890.—IDEM, in Commer’s _Jahrbuch für Philosophie und spekulative Theologie_, 1894 sqq.—*Dummermuth, O. P., _S. Thomas et Doctrina Praemotionis Physicae_, Paris 1886.—I. A. Manser, _Possibilitas Praemotionis Physicae Thomisticae_, Fribourg (Switzerland) 1895.—Joh. Ude, _Doctrina Capreoli de Influxu Dei in Actus Voluntatis Humanae_, Graz 1905.—Del Prado, _De Gratia et Libero Arbitrio_, 3 vols., Fribourg (Switzerland) 1907.—P. Garrigou-Lagrange, _S. Thomas et le Néomolinisme_, Paris 1917. On the Augustinian side: Card. Norisius, _Vindiciae Augustinianae,_ Padua 1677.—*Berti, _De Theologicis Disciplinis_, 8 vols., Rome 1739 sqq.—Bellelli, _Mens Augustini de Modo Reparationis Humanae Naturae_, 2 vols., Rome 1773.—L. de Thomassin, _Mémoires sur la Grâce, etc._, Louvain 1668. For a list of Molinistic and Congruistic authors see pp. 269 sq. Article 2. Molinism And Congruism The point in which these two systems meet, and in regard to which they differ from Thomism and Augustinianism, is the definition of efficacious grace as _efficax ab extrinseco sive per accidens_.