According to him, we use the Illative sense all the time. For instance:
We are in a world of facts, and we use them; for there is nothing else to use. We do not quarrel with them, but we take them as they are, and avail ourselves of what they can do for us. It would be out of place to demand of fire, water, earth, and air their credentials, so to say, for acting upon us, or ministering to us. We call them elements, and turn them to account, and make the most of them. [9:1]Which provokes the response: dude, have you ever actually met a scientist? Demanding the credentials, so to speak, of apparent fact is pretty much their whole modus operandi. Now, we might say: no--no, not that, Newman is talking about the ordinary man and woman in the street. OM/WITS takes it kind-of on trust that the world works the way the world works; the manifold mysteries of existence get sealed into common-sense Illatively. But I don't think this is right either. More specifically, people quarrel with facts all day every day; people prefer fantasy to fact, people ignore fact, people translate fact into something more in tune with the song sung inside their cranium. Religions themselves are, in part, eloquent quarrels with the facts of (as it might be) personal death and extinction; pain and suffering; meaninglessness. And so on.
Put it another way: Newman compares his Illative sense with Aristotle's phronesis, or judgment. But phronesis can be wrong, of course. Newman doesn't seem interested in the valences of a wrongheaded Illative judgment.
He touches on it, of course; but seems to make the case that our Illative sense is in one iteration precisely that 'common sense' that tells us something is daft, without needing to prove it ... that is able to distinguish what merits our sincere faith and what doesn't, just on gut:
Unless we had the right, when we pleased, of ruling that propositions were irrelevant or absurd, I do not see how we could conduct an argument at all; our way would be simply blocked up by extravagant principles and theories, gratuitous hypotheses, false issues, unsupported statements, and incredible facts. There are those who have treated the history of Abraham as an astronomical record, and have spoken of our Adorable Saviour as the sun in Aries. Arabian Mythology has changed Solomon into a mighty wizard. Noah has been considered the patriarch of the Chinese people. The ten tribes have been pronounced still to live in their descendants, the Red Indians; or to be the ancestors of the Goths and Vandals, and thereby of the present European races. Some have conjectured that the Apollos of the Acts of the Apostles was Apollonius Tyaneus. Able men have reasoned out, almost against their will, that Adam was a negro.Gracious! Imagine that last notion! Surely the subcionsciously racist Illative sense cannot be wrong in dismissing it?
Adam was Illatively a white male. Wrong on both counts! Who'd have thunk! Or to sum this whole post up in one word: a piece of 21st-century terminology that equates to Newman's Illative Sense? Truthiness.