If you’ve read the Iliad, then you know that whenever the Greeks weren’t fighting, they were wrangling about women, sacrificing to the gods, boasting, feeling sorry for themselves, eating barbecue, or competing athletically. One of the most popular competitions was racing. The impromptu racecourse always had an outbound and an inbound leg, like an inverted U. Contestants dashed for a designated tree or rock, rounded it, and returned to the starting line.
Aristotle used this inverted U as a metaphor for the path of human reasoning. First we reason up to first principles; that’s the outbound leg of the race. Then we reason down from first principles to more detailed conclusions; that’s the inbound leg.
In disciplines like geometry, we traverse the outbound leg so quickly that we hardly notice doing so; we assent to the axioms almost instantly. But imagine a dull student for whom assent doesn’t come quite so easily. Though the axioms are evident in themselves, they aren’t yet evident to him. “Teacher, why does the whole have to be greater than the part? Couldn’t be less sometimes? And why do two things equal to a third thing have to be equal to each other? Couldn’t they be unequal now and then?”
The teacher can’t prove the axioms to the boy, because there are no deeper axioms to prove them from. That’s the whole point of first principles. But there may be other ways to help the boy assent. The teacher might draw pictures. He might give examples. He might show some of the absurd results of assuming the axioms to be false. Eventually the boy gets it. The axioms click, and he assents.
John Henry Newman called this outbound mode of reasoning, so different from formal logic, the “grammar of assent.” Though we hardly give it thought in geometry, in theology and ethics it is almost the whole action. Even in skeptical times like our own, it is rare to find anyone who refuses assent to geometrical axioms. But about the first principles of ethics, people argue. “Teacher, why is it wrong to do gratuitous harm to my neighbor? Why not just do as I want?”
This sort of difficulty arises not just among dull students, but even – and especially – among the most powerful and intelligent people in our culture. Scholars, jurists, and other agents of culture openly avow that there is no such thing as intrinsic evil; that moral distinctions are the product of irrational animus; that the end justifies the means; that since truth is whatever works, successful lies aren’t lies; and that the weak have less claim on our protection than the strong. Their assumption is “If a first principle isn’t evident to me, then it can’t be evident in itself.” Thus, to refute a first principle, all I have to do is –- deny it. This is the grammar of dissent.
Why is the grammar of dissent more troublesome in ethics than in geometry? I think it would be just as prominent in geometry, if geometry presented us with equally strong motives for defending what is obviously false. Not many people have vested interests in trying to show that two things equal to a third thing aren’t really equal to each other. But a lot of people have vested interests in trying to show that their lies are really truths, or their injustices are really just. To put it another way, we aren’t dealing with honest confusion, but with dishonest confusion – with error that is motivated by corruption.
And why is the grammar of dissent more prominent at the highest strata of the culture? Since power wakens such great temptations to do wrong, it generates equally great yearnings to justify doing wrong. Those who have not only power but intelligence are more skillful at making up excuses. Intelligence is a gift -- but never confuse being smart with having wisdom.