Tradition is existing knowledge. A tradition is a group of related ideas that have lasted for a long time. In some cases people have spent that time trying to improve the ideas. We'll call that a dynamic tradition because it changes over time. In other cases, the focus has been on keeping the tradition exactly the same over time. We'll call that a static tradition because it does not change. Although these approaches are contradictory, some traditions are mixed.
Dynamic traditions are important because they contain some of our best knowledge. Today, they contain only the best ideas any participants have thought of in the whole history of the tradition. I don't mean they are perfect, but if they missed a good idea, it was despite people's efforts, not intentional. They do a pretty good job of gathering the best ideas, and keeping those around, and discarding ideas that are discovered to be mistaken. The reason dynamic traditions are especially valuable is the sheer amount of thought, criticism and error correction that has gone into them from many people.
Just because traditions contain valuable knowledge doesn't mean they are always right. Sometimes they aren't. I shouldn't defer to traditions just because a lot of smart people didn't see any way to improve them further. I should defer if I don't see any way to improve them further.
If I make up a new idea, and I don't see any way to improve it further (in 20 minutes of thought), then it's not particularly reliable. I could easily have missed something. With a tradition, perhaps thousands of people put in twenty minutes of thought, and some others put in years, so even if I don't see any way to improve things, and even if I don't know much about the subject, it has an advantage over just making something up myself.
All the knowledge in traditions can be intimidating. And no one has time to carefully and critically go through all the details of all the traditional knowledge they use. That's OK. But one should bear in mind two things. First, if something goes wrong — if there seems to be a problem — then relying on tradition isn't good enough. It's not working, and you'll need to tweak something or find another tradition. And second, a thoughtful person should critically evaluate some traditions. It's your choice which, but everyone ought to be good at something and have the experience of trying to improve some knowledge. Everyone should put some serious thought into some area. There isn't much point to life if I don't seriously think about some parts of it.
In the case of a disagreement, an appeal to tradition is invalid. The tradition might be wrong and someone thinks it is. To address that disagreement, I have to consider their criticism of the tradition, any alternative ideas they have, and any arguments in favor of the traditional idea, and then try to work out what is true. Traditions containing people's best ideas of the past won't always be the best ideas anyone thinks of in the future. The biggest value of traditions is they can often give useful ideas that are not controversial, or starting points which partially solve problems.
In a disagreement, although we can't say, "This is true because a lot of smart people didn't see anything wrong with it, and who are you to say they missed something?" the fact that something is a tradition is not irrelevant either. Dynamic traditions have, over the years, faced a lot of criticism. They often already include explanations of why common criticisms of the tradition are mistaken. Major traditions have existing literature that provides arguments and ideas on the subject. This literature can answer many disagreements, which are often made in ignorance.
When we find something wrong with a tradition, if at all possible we should improve the tradition, not abandon it. We should seek a way to modify the tradition but also retain existing knowledge. To keep the most existing knowledge, our change should be as small as possible to solve the problem. If we were to start over from scratch, we may avoid the flaw we found, but we're not perfect and our new ideas will contain other flaws. And new ideas won't have the benefit of decades or centuries of people trying to find and correct flaws. We should consequently be respectful of tradition even as we find errors in it, and try to improve it with new ideas of our own.
Static traditions are different. Although they've been around a long time, no one has been trying to find mistakes in them, so they aren't very useful. Nor are they innocuous. Consider: why does the static tradition still exist? Why didn't it disappear after its original advocates died? With a dynamic tradition, it's passed on to the next generation because people find it useful, and teach it. A static tradition, too, must have some mechanism for being passed on. But it can't be that people voluntarily learn it due to its usefulness. Because it never changes, and never corrects errors, it's not very useful. Instead, people must in some way be tricked or fooled into it, or indoctrinated, or forced, or brainwashed. Often they are pressured, and made to feel bad, sinful or guilty if they do not follow the tradition. But controlling people's emotions is difficult. Because people are creative and will try to defend themselves, it takes a lot of knowledge to reliably control or manipulate them. Where does that knowledge come from?
Static traditions are not actually entirely static. The main ideas, doctrine or dogma is kept constant. But the way of passing it on changes. The more people try to preserve the tradition unchanged, and make sure it will last forever, the more creativity they put into mechanisms for transmitting the tradition to the next generation.
All traditions face a selection effect. For a tradition to last, it has to be passed on from older people to younger people. But only so many ideas can be taught to the next generation. Children are only in school, and in their parents' home, for so many years. The amount of ideas is large, but it's limited. Only a certain amount of tradition can fit. Only the ones that are better at being passed on will make the cutoff.
Dynamic traditions compete by being as useful as possible. Thus the selection effect pushes them to be better and better. They try to be true, and people like the truest ones so much that they teach them to children.
Static traditions compete differently. They can't compete with good ideas directly, so they use other approaches such as manipulating or controlling people. In short, in some way they disable the person's creativity so he doesn't realize the tradition is low on useful truth content, and doesn't think of alternative ideas against which a static tradition can't compete. The selection effect for static traditions makes them worse, not better. Any static tradition that fails to create a permanent blind spot in the person runs a serious risk that one day he'll realize it's not a great tradition and doesn't have a lot of useful knowledge. And if he realizes that, whether he ever changes his mind or improves himself, what he won't want to do is teach it to his kids. There will never come a time when his children have some problem or question, and he thinks if he teaches them this tradition it will help them, since he knows it is not useful.
Traditions are important because they contain our best knowledge collected over the years. But they can also be dangerous. Static traditions can induce blind spots in people and be bad for everything except getting themselves taught to children. It is up to us to consider which traditions are which.
Acknowledgments: some ideas presented are modified from, or inspired by, ideas from Karl Popper, Ayn Rand, William Godwin, Edmund Burke, David Deutsch and Thomas Szasz.