In theology and philosophy, probabilism (from Latin probare, to test, approve) holds that in the absence of certainty, probability is the best criterion. Thus it is applied in connection with casuistry for the view that the layman in difficult matters of conscience may safely follow a doctrine inculcated by a recognized Doctor of the Church. This view was originated by the monk Molina (1528 - 1581), and has been widely employed by the Jesuits. In philosophy the term is applied to that practical doctrine which gives assistance in ordinary matters to one who is skeptical in respect of the possibility of real knowledge: it supposes that though knowledge is impossible a man may rely on strong beliefs in practical affairs. This view was held by the skeptics of the New Academy (see skepticism and CARNEADES). Opposed to "probabilism" is "probabiliorism" (Latin probabilior, "more likely"), which holds that when there is a preponderance of evidence on one side of a controversy that side is presumably right.
Academic skeptics accept probabilism, while Pyrrhonian skeptics do not.
The original version of this article is based on an article from the 1911 Encyclopedia Britannica.