Ideas don't move through history by themselves. They need something to carry them.
A religious teaching needs language, teachers and eventually institutions. A political principle may become a constitution, a law or a court decision. Scientific knowledge moves through universities, journals, laboratories and textbooks. Even a family story needs someone to keep telling it.
The interesting part is what happens along the way. We sometimes talk about an idea as though there were a clean version somewhere outside the world and a corrupted version after human beings got involved, but I'm not sure the clean version ever existed. An idea that can't be communicated, interpreted or acted upon may be an idea, but it isn't doing much yet. Eventually somebody has to give it a form, and that introduces constraints.
Consider a simple principle like equality. It sounds reasonably complete until we try to enact it. Equal in what sense, and before which institutions? Does equality require treating everyone identically, or can different treatment sometimes be necessary to produce equal standing? Who decides, and what happens when equality conflicts with another principle we also value?
The moment the principle enters the world, people have to start answering questions that weren't contained in the word itself. Now the idea has acquired a history, and that history matters because later generations don't inherit the original idea alone. They inherit previous attempts to put it into practice.
The American founding provides an unusually visible example. The language of equality appeared alongside slavery. That contradiction didn't make the language meaningless; people later used the stated principle to challenge institutions that violated it. It also didn't make the contradiction imaginary. Both traveled forward.
A principle can constrain the institution carrying it even when the institution fails to live up to the principle, and the reverse can happen too. An institution can gradually change what people understand the principle to mean. Constitutions are interpreted. Religious traditions develop schools and doctrines. Scientific institutions decide what counts as evidence. Political movements discover which arguments attract supporters.
Sometimes those changes are corruptions. Sometimes they're improvements. Sometimes they're adaptations necessary for an idea to survive circumstances its original advocates never encountered. Usually the interesting cases contain some combination of all three, which makes historical inheritance difficult to judge from a single moment.
Take an institution that compromises in order to survive. From one position, the compromise may look like practical wisdom. From another, it may look like abandonment of the thing the institution was supposed to preserve. Both interpretations might even become more or less convincing with time because we get to see consequences the people making the original decision couldn't. They had to act without them.
This is why I'm increasingly interested in the distance between what an institution says and what it actually does, although not because every difference proves hypocrisy. Sometimes it does. Other times the difference tells us that the principle was incomplete, the circumstances changed, two legitimate obligations collided, or the available institution simply couldn't carry everything people were asking it to carry.
The gap is information.
A newspaper can say it serves its community, but that claim doesn't establish that it does. You can look at what it covers, who can reach it, what happens when it makes a mistake, whether the institution changes when the community changes, and whether its behavior still resembles the reason people trusted it in the first place.
The same test works surprisingly well on much larger institutions. What does the constitution say, and what does the government do? What does the religion teach, and what does the institution reward? What does th