716. The claim of Probabilism is that, in all the cases given above, he who follows an opinion excusing him from obligation, may act with a practically certain conscience and be free of all moral guilt, if the opinion is theoretically and seriously probable. The arguments for this thesis are of two kinds: (a) extrinsic proofs, from the approval given Probabilism by the Church and the favor it has enjoyed among moralists; (b) intrinsic proofs, from the nature of law and obligation, and the superiority of Probabilism in practice. 717. Extrinsic Arguments.--(a) The Church gave explicit approval to Probabilism by praising the theological works of St. Alphonsus in which Probabilism is defended; she gave and continues to give implicit approval by the freedom she has granted to the teachers of this system from the days of Bartholomew Medina, its first expounder (1527-1581), down to the present. The Church even makes use of the principles of Probabilism in interpreting her own laws, as is evidenced by such rules of law as the following in the Decretals: “Things that are odious should be understood strictly, things that are favorable widely” (Rule 15); “Where the law is doubtful, follow the minimum” (Rule 30); “Where the lawgiver could have spoken more clearly, the interpretation should be against him” (Rule 57); “The kinder interpretation should be given penal laws” (Rule 89). (b) In the Patristic and medieval periods Probabilism had not been scientifically formulated, but many of the Fathers and early Doctors solved cases probabilistically, and there are not a few passages in the great theologians before the sixteenth century which enunciate the same principles as those advocated by Probabilists. When the system was formulated by Medina in 1577, it met with universal favor among Catholic moralists, and, though it suffered an eclipse from the middle of the seventeenth to the middle of the eighteenth century, it has been growing in influence since the days of St. Alphonsus, and appears today to have recovered its former preeminence. Among its adherents are some of the greatest names in the history of theology, and it is not confined to any particular school or body. 718. Objections of Equiprobabilists.--(a) The praise given to St. Alphonsus by the Church reflects no glory on Probabilism, since the Saint rejected Probabilism and professed Equiprobabilism. Further, more than one Pope, and especially Innocent XI (1676-1689), has expressed a dislike for Probabilism, while the silence of others does not mean more than toleration. The legal axioms used by canonists apply to the external forum, and cannot be used equally in the forum of conscience. (b) Probabiliorism had the field before Probabilism, having been formulated and defended before Medina appeared, and it is that more ancient system that is represented today in a milder form as Equiprobabilism.