A third ideal that has made its way in the modern world is reliance on reason, especially reason disciplined and enriched by modern science. An eternal basis of human intercommunication is reason.
I have the ordinary experience of being anonymous when I'm in an airplane talking to air-traffic control, and they don't know who they're talking to. I have a lot of common experiences.
In an area where nothing was known, medicine had to draw on social lore.