One needs but to apply to theology the epistemological principles and criteria furnished by philosophy to perceive that the Catholic dogma is as reasonable as the Protestant theory is absurd. The Protestant syllogism: “I know with a certainty of faith that the penitent sinner who does his share, is justified through the grace of Christ; now, I, who am a penitent sinner, know with a certainty of faith that I have done my share; therefore, I know with a certainty of faith that I am justified,” may be formally correct, but the minor premise embodies a material error, because no man knows with a certainty of faith that he has done his share, unless it be specially revealed to him by God. No matter how sure I may feel of my own goodness, I have no certainty of faith, such as that which Mary Magdalen had, or that which was vouchsafed to the penitent thief on the cross, that I am justified. It is one of the approved rules of syllogistic reasoning that “the conclusion must follow the weaker premiss.”(1168) Hence, in the above syllogism the certainty cannot be of faith, but human and moral only. We do not mean to deny that God may grant to this or that individual a certainty of faith with regard to his justification; in fact theologians expressly teach that in such a rare and exceptional case the privileged person would be obliged to believe in his own justification, _fide divinâ_.(1169)
β) Can any one, without a special revelation, be _theologically_ certain that he is justified? Theological certainty (_certitudo theologica_) is the result of a syllogism which embodies an article of faith in one of its premises and an obvious truth of reason in the other. Ambrosius Catharinus(1170) stands alone among Catholic theologians in holding that there are rare cases in which men do have a theological certainty as to their justification without a private revelation. All other writers deny the possibility: (1) because Scripture and Tradition do not countenance the proposition; (2) because there are no criteria available for such certainty outside of private revelation, and (3) because the Tridentine Council censured the assertion “that they who are truly justified must needs, without any doubt whatever, settle within themselves that they are justified.”(1171)