Now ask him if Christianity should play an official role in the German government. Or if he objects to people practicing cultures other than German in Germany. Both of those would be radically far-right in North America, but are pretty standard in Europe.

What’s going on here is that people tend to arrange themselves along a left-to-right line, but where exactly in the multidimensional space of viewpoints that line cuts through varies dramatically between times and places. It even inverts - your Prussian conservative would have taken a much dimmer view of free markets than a contemporary to their political left.

My mental model of the right-left dichotomy:

• “right” = cynical + evil
• "left" = good + naive

Anything more complex and the labels hit their limits.

I think a better one is acceptance of change.

• Right: Resistant to change
• Left: Accepting of change

Sometimes change is good, sometimes the world is not ready. I think this aligns closely with “cynical” and “naïve” but just makes it more abstract.