The lecture on Cardinal John Henry Newman’s Grammar of Assent, by Duke Divinity School Professor Paul Griffiths, reminded me what I miss about college. To think of such high and fundamental reasoning being a subject of everyday contemplation and discussion! (We strive for some small taste of that, on Anchor Rising, but it’s just not the same when partaken during 15-minute coffee breaks on the construction site.)
Portsmouth Abbey teacher Dimitra Zelden gave a humorous introduction of the speaker:

(The remainder of Prof. Griffiths’ speech is available in the extended entry of this post.)
Among the quotations that I jotted in my notebook (a neat imprinted one included in the Portsmouth Institute’s registration package) is: “Credulity is the first principle of good cognitive functioning.” Put differently, thought must be premised on belief in something. This belief — a general sense, really, of how the world functions — forms an “illative sense” that intellectual and even empirical argumentation cannot ultimately change.
At first stating, the conclusion seems bleak. Prof. Griffiths denied the possibility of ultimately convincing others of a proposition to which their illative sense will not allow them to assent, because the first belief necessary for a change of position — that the world can be such that a proposition to which we’re opposed can be true — is not subject to rational dispute. “When we disagree fundamentally, argument is almost always useless.”
In response to an audience question about whether argument therefore comes down to a resort to force, Griffiths offered the alternative strategies of “prayer and fasting” and the emphasis on (I’d term it) argument by aesthetics. Appeal to people’s sense of beauty, of which truth is a natural component.
A number of directions for exploration present themselves. First, it seems to me that the end of argumentation’s fruitful run brings us to the realm of politics, and that democracy’s signal purpose is to redirect the impulse of sides to impose their views on those who disagree (which, objectively considered, circumstances will sometimes require) toward a non-violent process. Second, Griffiths’ thesis (or Newman’s, if the speaker was not adding his own extrapolation) risks eliding everything between intellectual argument and political or military force for those habituated to emphasize rationality.
It is critical to be aware that argument is really just one form of appeal. Debate appeals to logic. Beauty appeals to aesthetics. Violence appeals to survival instinct. Furthermore, there’s no border between logic and aesthetics; it’s more of a spectrum, with the upshot being a conclusion that Christians have understood even where they could not state it: To convince ultimately requires a change in illative sense, which must be accomplished through proof of action. That is to say charity, as well as an attractive relationship with the world, whether comfortable or challenging. Christ’s indomitability — even as His material circumstances thrust Him toward the cross — stands as the stark model.