(Lat. probabilior, “more likely”). A term used in Roman Catholic theology when the question was asked, What ought a Christian to do when duties seem to clash? What if Christian freedom suggests course A, but legalistic considerations point to course B? Two answers were given: (1) arguments in favor of A and B should be examined, and that course followed which seems more probably correct (hence Probabiliorism); (2) provided the nonlegalistic line of conduct can be defended, even as less probable than the legal, it may be followed (Probabilism*).

Acute controversy on the issue broke out in 1656 when Blaise Pascal,* the Probabiliorist Jansenist, in his Lettres provinciales lashed out at the Probabilist Jesuits for their hypocrisy, stressing that their view permitted a man to do anything, however wicked, which he could successfully rationalize. Probabiliorism was triumphant in the ensuing battle, but Probabilism was revived later (with some safeguards) by A. Liguori,* and is now official Roman Catholic teaching.