L: Rhetorical persuasion does not track truth in the way that good arguments do. The best way for us to collectively come to truth is well-reasoned arguments presented in a dry and rigorous way, avoiding rhetorical flourishes. Rhetoric makes weaker arguments appear stronger than they are and a practice of giving rhetorically powerful arguments can make stronger arguments appear weaker.
R: Rhetoric appeals to emotions and emotions are truth-tracking, albeit their reliability, except in the really virtuous individual, may not be high. So I don't believe that rhetorical persuasion does not track truth. But I will grant it for our conversation, L. Still, you're forgetting something crucial. People have an irrational bias against carefully listening to arguments that question their own basic assumptions. Rhetoric and other forms of indirect argumentation sneak in under the radar of one's biases and make it possible to convince people of truths that otherwise they would be immune to.
L: Let's have the conversation about the emotions on another day. I suspect that even if emotions are truth-tracking, in practice they are sufficiently unreliable except in the very virtuous, and it is not the very virtuous that you are talking of convincing. I find your argument ethically objectionable. You are placing yourself intellectually over other people, taking them to have stupid biases, sneaking under their guard and riding roughshod over their autonomy.
R: That was rhetoric, not just argument!
L: Mea culpa. But you see the argumentative point, no?
R: I do, and I agree it is a real worry. But given that there is no other way of persuading not very rational humans, what else can we do?
L: But there are other ways of persuading them. We could use threats or brainwashing.
R: But that would be wrong!
L: This is precisely the point at issue. Threats or brainwashing would violate autonomy. You seemed to grant that rhetorical argument does so as well. So it should be wrong to convince by rhetorical argument just as much as by threats or brainwashing.
R: But it's good for someone to be persuaded of the truth when they have biases that keep them from truth.
L: I don't dispute that. But aren't you then just paternalistically saying that it's alright to violate people's autonomy for their own good?
R: I guess so. Maybe autonomy isn't an absolute value, always to be respected.
L: So what objection do you have to convincing people of the truth by threat or brainwashing?
R: Such convincing—granting for the sake of argument that it produces real belief—would violate autonomy too greatly. I am not saying that every encroachment on autonomy is justified, but only that the mild encroachment involved in couching one's good arguments in a rhetorically effective form is.
L: I could pursue the question whether you shouldn't by the same token say that for a great enough good you can encroach on autonomy greatly. But let me try a different line of thought. Wouldn't you agree that it would be a unfortunate thing to use means other than the strength of argument to convince someone of a falsehood?
R: Yes, though only because it is unfortunate to be convinced of a falsehood. In other words, it is no more unfortunate than being convinced of a falsehood by means of strong but ultimately unsound or misleading arguments.
L: I'll grant you that. But being convinced by means of argument tracks truth, though imperfectly. Being convinced rhetorically does not.
R: It does when I am convincing someone of a truth!
L: Do you always try to convince people of truths?
R: I see what you mean. I do always try to convince people of what I at the time take to be the truth—except in cases where I am straightforwardly and perhaps wrongfully deceitful, sinner that I am—but I have in the past been wrong, and there have been some times when what I tried to convince others of has been false.
L: Don't you think that some of the things you are now trying to convince others of will fall in the same boat, though of course you can't point out which they are, on pain of self-contradiction?
R: Yes. So?
L: Well, then, when you strive to convince someone by rhetorical means of a falsehood, you are more of a spreader of error than when you try to do so by means of dry arguments.
R: Because dry arguments are less effective?
L: No, because reasoning with dry arguments is more truth conducive. Thus, when you try to convince someone of a falsehood by means of a dry argument, it is more likely that you will fail for truth-related reasons—that they will see the falsehood of one of your premises or the invalidity of one of your inferences. Thus, unsound arguments will be more likely to fail to convince than sound arguments will be. But rhetoric can as easily convince of falsehood as of truth.
R: I know many people who will dispute the truth conduciveness of dry argument, but I am not one of them—I think our practices cannot be explained except by thinking there is such conduciveness there. But I could also say that rhetorical argument is truth conducive in a similar way. The truth when attractively shown forth is more appealing than a rhetorically dressed up falsehood.
L: Maybe. But we had agreed to take for granted in our discussion that rhetorical persuasion is not truth tracking.
R: Sorry. It's easy to forget yourself when you've granted a falsehood for the sake of discussion. Where were we?
L: I said that reasoning with dry arguments is more truth conducive, and hence runs less of a risk of persuading people of error.
R: Is it always wrong to take risks?
L: No. But the social practice of rhetorical presentation of arguments—or, worse, of rhetorical non-argumentative persuasion—is less likely to lead to society figuring out the truth on controversial questions.
R: Are you saying that we should engage in those intellectual practices which, when practiced by all, are more likely to lead to truth?
L: I am not sure I want to commit myself to this in all cases, but in this one, yes.
R: I actually think one can question your claim about social doxastic utility. Rhetorical persuasion leads to a greater number of changes of mind. A society that engages in practices of rhetorical persuasion is likely to have more in the way of individual belief change, as dry arguments do not in fact convince. But a society with more individual belief change might actually be more effective at coming to the truth, since embodying different points of view in the same person at different times can lead to a better understanding of the positions and ultimately a better rational decision between them. We could probably come up with some interesting computation social epistemology models here.
L: You really think this?
R: No. But it seems no less likely to be correct than your claim that dry argument is a better social practice truth-wise.
L: Still, maybe there is a wager to be run here. Should you engage in persuasive practices here that (a) by your own admission negatively impact the autonomy of your interlocutors and (b) are no more likely than not to lead to a better social epistemic state?
R: So we're back to autonomy?
R: But as I said I see autonomy not as an absolute value. If I see that a person is seriously harming herself through her false beliefs, do I not have a responsibility to help her out—the Golden Rule and all that!—even if I need to get around her irrational defenses by rhetorical means?
L: But how do you know that you're not the irrational one, about to infect an unwary interlocutor?
R: Are you afraid of being infected by me?
L: I am not unwary. Seriously, aren't you taking a big risk in using rhetorical means of persuasion, in that such means make you potentially responsible for convincing someone, in a way that side-steps some of her autonomy, of a falsehood? If by argument you persuade someone, then she at least has more of a responsibility here. But if you change someone's mind by rhetoric—much as (but to as smaller degree) when by threat or brainwashing—the responsibility for the error rests on you.
R: That is a scary prospect.
R: But sometimes one must do what is scary. Sometimes love of neighbor requires one to take on responsibilities, to take risks, to help one's neighbor out of an intellectual pit. Taking the risks can be rational and praiseworthy. And sometimes one can be rationally certain, too.
L: I am not sure about the certainty thing. But it seems that your position is now limited. That it is permissible to use rhetorical persuasion when sufficiently important goods of one's neighbor are at stake that the risk of error is small relative to these.
R: That may be right. Thus, it may be right to teach virtue or the Gospel by means that include rhetorical aspects, but it might be problematic to rhetorically propagate those aspects of science or philosophy that are not appropriately connected to virtue or the Gospel. Though even there I am not sure. For those things that aren't connected to virtue or the Gospel don't matter much, and error about them is not a great harm, so the risks may still be doable. But you have inclined me to think that one may need a special reason to engage in rhetoric.
L: Conditionally, of course, on our assumption that rhetoric is not truth-conducive in itself.
R: Ah, yes, I almost forgot that.