When seriously arguing for (or against) a simple policy or practice, you probably aren’t being intellectually honest if you aren’t willing to explicitly list all the reasonably predictable consequences that you think said policy or practice will plausibly have – benefits for some parties, harms to some, and more or less neutral consequences for others, just clinically jotted down on a piece of paper or something. Ideally you should also ask someone holding a differing opinion if they would agree on the list, because in principle, it only includes straightforwardly descriptive statements and not value judgments. (If you’re playing on hard mode, also try to come to an agreement on the approximate magnitudes of each effect you’ve written down.)
This should help to ensure that differing opinions about policy matters are not primarily rooted simply in epistemic disagreements about empirical matters (which are often easier to begin to solve, and, uh, should not warrant a deep hatred of the people on the other side with their profoundly disturbing alien values) as well as reduce certain biases. We typically put disproportionately little weight on the fact that not all of the consequences of whatever we’re currently promoting are going to be 100% positive for everyone forever: someone is almost certainly going to suffer as well, or there probably wouldn’t be much to argue about in the first place. This suffering always seems like a trivial inconvenience to us, and sometimes it is, but sometimes it isn’t, quite independently of how insignificant we’re personally inclined to believe it is. This is why we need to address it explicitly instead of just accepting our immediate, likely flawed, intuitive judgment. All the information we use in the process is often pretty obvious, but we still don’t really take it into account until we explicate it (perhaps a bit like how being aware of the hidden zero when making personal decisions will often lessen temporal discounting).
After considering the list, you’re free to point out how small or easily treatable the resulting suffering is relative to the benefits the policy will provide, of course. But you have to be able to make a list – without omitting real, relevant consequences just because they can be used to support an opinion opposing yours. If the policy is any good in the first place, it should be able to face all of reality.
Since I currently seem to be arguing for a practice of listing both the negative and the positive consequences of whatever practices one is arguing for, and have so far mainly focused on why this would be a good idea, I guess I’m sort of required to add some caveats too. Cognitively speaking it does get quite taxing to consciously assess decisions in this way, especially when you’re discussing something very complicated or novel and unpredictable. But this means it’s probably a good idea to gather more evidence before applying the policy, to make it less complicated or unpredictable: so maybe argue for gathering the needed evidence instead. Still, it’s true that sometimes when we’re not talking about a critically important decision affecting large amounts of people, our heuristics and intuitions are a more cost-effective decision-making tool, and will do just fine. Another discouraging point is that since practically nobody else is immediately willing to play by these rules, and the majority of people are in any case going to be biased like this, you won’t accomplish much apart from making your own opinions look worse if you admit they may have bad effects too. This kind of thinking – reasoning that you have to keep promoting irrationality if you want to effectively participate in a largely irrational society – is absolutely terrifying, but unfortunately this doesn’t mean the conclusion isn’t true in some cases. Still, the list principle is good to keep in mind during debates in actually curious environments, when participants are actually aiming for a rational consensus: it will highlight important things about intellectual honesty, and help to locate the actual disagreements.