“You have no rational evidence for your beliefs.” Such an assertion is not likely to be the beginning of a fruitful discussion.
Now don’t get me wrong, I don’t mind disagreement. In fact, I would submit that it is hard to “lose” a truly thoughtful discussion. Even if you don’t bring your interlocutor around to your own way of thinking, you can nevertheless learn why someone else sees things differently, what sorts of considerations are most decisive, and which areas of your own articulation of the matter are in need of refinement.
But those sort of discussions do not begin with the assertion that your opinions are attributable to sheer prejudice, or idiocy, or provincialism. When that is the vibe, you are not dealing with someone who is really interested in exploring the issue with you. You are dealing with a cultural Sophist at best, a “swine” at worst (Matthew 7:6). How should you react?
Now when the Sophist Thrasymachus verbally assaulted Socrates in Book I of the Republic, shouting at him and calling him a sycophant, Socrates was not only able to defend himself, but he was able to eventually “tame” Thrasymachus. That is to say, Socrates calmed Thrasymachus down down and brought him to recognize the internal contradictions in his own position.
I would generally advise you to abandon hope for a similar outcome. This “taming” could only happen because this sophistical attack came in the midst of a philosophical discussion in the house of Socrates’s friend Cephalus. In other words, Thrasymachus was not in a position of power. By contrast, the Sophists you are likely to face in public life will generally be confident in their alignment with the political powers that be, so give up all hope of getting them to listen to you. Their goal will not be to achieve truth with you, but only to disenfranchise you as a rational agent, to humiliate you.
But why make it easy for them? Why not make them work for it a bit? In this post, I propose two lines of response to this sophistical attack, followed by a brief philosophical justification of each point. Neither line of response is necessarily going to win the argument. In fact, in some cases these responses may only antagonize the aggressor. Yet it is also possible that they might cause, in the immortal words of Sir Topham Hatt, “confusion and delay.” They might cause the aggressor to doubt himself slightly, or to at least spend more time justifying his attack. This will help to expose his Sophistry for any fair-minded and impartial observers.
“You claim that my position is irrational, that I have presented no evidence that rational person would have to respect. My question for you is just, ‘What makes you so sure?’ After all, it is not easy to know what should count as compelling evidence in regard to a particular question. Different levels of expertise in regard to a particular question will result in a different appreciation of just how compelling the evidence is. Were you to present me with some objectively amazing evidence in regard to a problem of astrophysics, it might seem like gibberish to me–as, apparently, my beliefs do to you.
So now, unfortunately, I have to inquire as to your particular expertise in these matters. Have you spent many hours of your life in discussions concerning the authority of the family vs. the authority of the state? Have you written books carefully assessing the cogency of the moral arguments I have presented to you in regard to human sexuality and conduct? If the answer is no, then perhaps you should be cautious in calling me a bigot. Until your own competence in regard to these matters is universally recognized, your own judgment of my opinion amounts to little more than a personal attack upon me.”
The above line of response defensively employs a dictum of classical and medieval philosophy, “all knowledge is received according to the mode of the receiver.” Think of knowledge here as beer. It is not the beer that determines how much of it is “in your glass,” but the size of your glass. You can pour more liquid into a 40 oz. container than into a shot glass. In like manner, some people are just so inexperienced with particular sorts of questions that they will not be able to understand the rationality of the evidence presented. This makes their appraisal of your arguments anything but infallible.
“You claim that my beliefs in regard to these matters have no rational basis. I disagree. But there is a deeper issue here: Since when do I have a duty to justify all of my beliefs to you, especially my beliefs about matters which are so fundamental and in line with the traditions of Western Civilization?
You hold me to a standard you yourself do not achieve. Do you have a rational justification for all of your beliefs–I’ll answer for you: no, because it is not possible to do so. First of all, nobody has that much time, and second, some realities are so fundamental that they don’t lend themselves to canned answers. We all know that we should love our children–but try to give a philosophical justification of that fact without sounding ridiculous. And if you were really being honest, you would also recognize that our beliefs are not entirely up to us. They reflect our experiences, the kinds of evidence that we have been privileged to encounter.
Your judgment, then, that my beliefs are “irrational” really amounts to nothing more than saying that you have simply lived a different life than me, and so your experiences have not led to the same beliefs as me. Why should your beliefs be preferable to mine? Are we somehow unequal? Are you superior to me?
The above line of argument is inspired from some moves made by the Protestant philosopher Alvin Plantinga, with a little Descartes thrown in for good measure. It seems to me that this line of argument is not decisive–a good answer can indeed be given to it. While we don’t have to justify every belief, we do have a human duty to justify our beliefs about the most important things. Mere assertion of belief is fine for which flavor of ice cream one prefers, but some questions are of far greater importance, and so it is fitting that they also receive rational justification. But someone thinking clearly enough to articulate that response is unlikely to have labelled your beliefs as mere bigotry in the first place.