People have conflicts.
Joe and Sue want to watch Netflix, but argue over which movie.
Joe's neighbor complains, "Your tree dropped leaves on my yard again. Come clean them up." Joe doesn't think it's his problem. Joe doesn't even rake his own yard much.
People trying to do things together have conflicts the most. The more you interact with someone, the more potential for a conflict. But even strangers have conflicts sometimes.
People try to deal with conflicts using compromises. A compromise involves each person giving up part of what they wanted in order to prevent conflict. They still want it, but they try to be happy with the other things they do get.
Joe agrees to watch a drama, rather than the action movie he wanted or the romantic comedy Sue wanted. He likes dramas OK, and he doesn't want to fight. He does want to spend time with Sue. He'd still rather have seen the action movie, though.
And Joe agrees to rake up the leaves, but only three times this fall, not twice a week like the neighbor wanted. Joe still doesn't want to do any raking, but he doesn't want to have a problem with his neighbor, either.
Joe is somewhat happy and somewhat unhappy about the movie and the raking. It's not too bad, he can put up with it, but it's not his ideal life either.
People expect life to be full of compromise. People look for compromises on purpose. They think it's the correct goal to aim for. They consider compromises the most you can expect in life.
A compromise is a partial solution. Some aspects of the problem are solved, like Joe isn't fighting with his wife or neighbor. But some things aren't solved. Joe has a mismatch between his ideal movie and the one he sees. Joe has a mismatch between his desire to rake (none) and the raking he does (some).
A common preference is a full solution. It's a way of proceeding that Joe (and everyone else involved) is fully happy with. Instead of getting part of what he wants, and making some sacrifices or compromises, Joe has no complaints about the outcome.
Common preferences mean that everyone (fully) prefers the same thing and they do that. They should be called "solutions". They could be called "proper" or "full" solutions. But, today, people frequently think a compromise is a solution.
Common preferences happen routinely in life. Many problems do get solved. Many interactions between people are fully happy, conflict free and sacrifice free. Most of life works fine.
But compromises are frequent.
Perhaps the biggest cause of compromises is that people think a compromise is a solution. They look for a compromise and do it on purpose. Their goal, to deal with the conflict, is to come up with a compromise (partial solution) rather than a common preference (full solution).
If people looked for more common preferences, they'd find more of them. Not even trying to think of common preferences is one of the easier things you can change to find more of them.
Common preferences are always possible because of the liberal point that people do not inherently have conflicts of interest. And because of the epistemology point that there is a truth of the matter – for every issue. There isn't a separate (incompatible) truth for each person.
Why are people so doubtful about common preferences that they frequently don't even look for them? Why are people willing to accept compromises as just how life works?
It's partly that they have a history of failing to find full solutions (not always failing, but reasonably often). But these bad experiences, including hundreds in early childhood, are not the whole issue.
People try to find solutions that fit everyone's current preferences, without much consideration for the possibility of people changing their preferences.
If you treat everyone's preferences as fixed/unchangeable/stuck – as a given, a premise of the situation – then compromises are the best you can do sometimes. You can brainstorm to try to find ideas that work for everyone, and sometimes succeed, and sometimes have to compromise.
When people say they changed their preferences, it's often assumed they don't really mean it. They are taken to be compromising, rather than to genuinely and fully prefer the new thing.
Actually, people can change their preferences. There is no reason a person has to be stuck with a preference that will cause a compromise, sacrifice or suffering.
Some preferences people have are incompatible with other people, and some preferences are incompatible with reality. Some preferences are mistaken. But people can learn better and change their mind. Preferences are ideas and have reasons, and can be rationally considered just like other ideas.
It doesn't make sense to want (prefer) things that won't work. It doesn't make sense for people to inflexibly have contradictory wants. It doesn't make sense for people to want the impossible (in contradiction to physics/nature).
If two people's preferences cannot both be satisfied, then at least one of them is mistaken. And he can learn why he's mistaken and change his mind.
Instead of only looking for solutions to get everyone their initial preference (which often works, but not always), people need to also consider changing their preferences.
Changing preferences is something people do frequently without it being a big deal. They find out a restaurant is closed and decide to go to a different one that's open. They find out their flight is delayed and decide to wait without getting upset at all. They had preferred the flight be on time, but they'd also planned some leeway in their trip and are OK with the delayed flight.
If I misread a price tag as saying $10 for a $100 item, then the cashier corrects me, I'll change my mind not to want to buy it anymore.
People can get upset about closed restaurants, late flights, and pricing misunderstandings. But usually they don't. Most of the time they don't even give it much thought and just move on. It's no big deal to change their mind.
But then when people think about the possibility of changing their mind, they remember the hard cases. They remember the times they did get upset and fail to change their mind. They remember the times they were unreasonable. They remember the disasters.
It's the minority of disasters that people need to handle better. It's changing their mind when they are stuck and upset that people find really hard.
The point here is to keep things in perspective. Changing your mind, including about preferences, is frequently pretty easy. It's not a rare or very hard thing. It's just there's some cases where it goes badly. So when we talk about how to do it, we're going to focus on the few hard cases, and we're going to remember it's not always hard. Those problem cases are special in some way, rather than just being normal life. (Some people, sadly, have some fights and compromises on a daily basis. But even then, they do dozens of activities every day and most of those activities go smoothly.)
So, how can you change your mind in the hard cases? It helps to think better, try harder, be a more rational person. But if that's all you could do, then you'd just kinda have to do your best and sometimes that wouldn't be good enough. Fortunately, there is a trick to make this easier. Do try to be the best person and most rational thinker you can be. Try to be nice, patient, honest, etc. But you can find common preferences, every time, without being some perfect saint.
The trick is recognizing your limits. The more you get stuck, the more you should think to yourself, "This is beyond me. This is too hard. This is a bad idea. I overestimated what I could accomplish. I should abort and do something within my current abilities."
If you can be reasonable enough not to want something that exceeds your skill and resources, then you can find common preferences.
The more things begin to go wrong, the more that should make it clear to you that you've overreached.
A reasonable person needs to develop their preferences and their skill at achieving preferences together. They need to co-evolve.
It's understandable that mistakes happen. Sometimes you'll be a little overly ambitious. You just need to be able to
1) Recognize this problem. Which is easy – when you're fighting with your family, looking for a compromise, having some disaster, etc, you know it!
2) Remember that these things shouldn't be happening and start getting less ambitious.
If you're trying to do a joint activity with someone, and it's turning into a fight, then you overreached. You made a mistake of trying to accomplish more than you had the skill for. That's alright. Just back off and do something simpler. And improve your skill and try again later.
If you're trying to do something impossible, that contradicts the laws of physics, that's your mistake. Back off, reconsider, learn more, figure out a better approach.
If you're trying to do something that causes a major clash with society, e.g. breaks a law, back off and understand what's going on better. Not every project you want to do is going to succeed immediately, as planned, on schedule. That's OK.
Failed common preferences are caused, in essence, by overreaching. By people wanting more than they have the knowledge and skill to get. This is a self-caused problem that's totally unnecessary.
Be reasonable. The pattern of life should be to first get knowledge and skill, and then second do stuff with it. If you want to go out of order on this, you're causing your own problems. When you make a mistake, which is OK, you need to recognize it (something is going wrong) and then think to yourself, "I made a mistake. I overreached." And then relax, calm down, and come up with a plan B that is within your current abilities (including current ability to coordinate and cooperate with other people). Even if that's really minimal, that's OK, do that. This is, overall, a very nice lifestyle that's way better than stubbornly wanting things that are beyond you. If it's so great, you can get it later, when you're actually ready. Trying to get something before you know how is just dumb, so don't be dumb and change your mind.
This is a big and tricky topic. So I gathered some additional reading to help. This list should be treated as a resource for your benefit, not a checklist where you're pressured to tick every box. And, yes, they all discuss common preferences even though you wouldn't guess it from some of the titles!