Newman John Henry (1801–90), English prelate and philosopher of religion. As fellow at Oriel College, Oxford, he was a prominent member of the Anglican Oxford Movement. He became a Roman Catholic in 1845, took holy orders in 1847, and was made a cardinal in 1879. His most important philosophical work is the Grammar of Assent (1870). Here Newman explored the difference between formal reasoning and the informal or natural movement of the mind in discerning the truth about the concrete and historical. Concrete reasoning in the mode of natural inference is implicit and unreflective; it deals not with general principles as such but with their employment in particular circumstances. Thus a scientist must judge whether the phenomenon he confronts is a novel significant datum, a coincidence, or merely an insignificant variation in the data. The acquired capacity to make judgments of this sort Newman called the illative sense, an intellectual skill shaped by experience and personal insight and generally limited for individuals to particular fields of endeavor. The illative sense makes possible a judgment of certitude about the matter considered, even though the formal argument that partially outlines the process possesses only objective probability for the novice. Hence probability is not necessarily opposed to certitude.
In becoming aware of its tacit dimension, Newman spoke of recognizing a mode of informal inference. He distinguished such reasoning, which, by virtue of the illative sense, culminates in a judgment of certitude about the way things are (real assent), from formal reasoning conditioned by the certainty or probability of the premises, which assents to the conclusion thus conditioned (notional assent). In real assent, the proposition functions to ‘image’ the reality, to make its reality present.
In the Development of Christian Doctrine (1845), Newman analyzed the ways in which some ideas unfold themselves only through historical development, within a tradition of inquiry. He sought to delineate the common pattern of such development in politics, science, philosophy, and religion. Although his focal interest was in how religious doctrines develop, he emphasizes the general character of such a pattern of progressive articulation. F.J.C.