I ran across this distinction teaching through Republic this fall, and I think it might be worth something to us evangelical Christians.
According to Plato, the kind of philosophical talk that goes on in government bodies is eristic, a conversation that assumes that the yes-or-no vote is the culmination of all valid talk. The possibilities of eristic are rather limited: either all interlocutors remain on the “sides” that they started on, or some or all move from one “side” to another. The “sides” themselves remain constant in an eristic.
In a dialectic, on the other hand, conversation progresses when one person asserts a position, another negates it, and someone asserts a novum, a new idea informed by the negation. Then someone might or might not try to negate the new assertion, and so on. While the eristic has only two outcomes, both predetermined, the dialectic can actually go new places.
This is not to say that eristic might not have its place sometimes, but I do wonder whether the common modern phenomenon, the disengagement from a conversation with an exhausted “We can talk about this all day, but neither is going to change the other person’s mind,” is the product of our modern forgetting how to do dialectic.