I visit Berlin and puzzle

Just back from Berlin where I couldn’t resist posing at the local metro station under a sign indicating the exit for Karl Marx Alley (boulevard really), Peace Street and The Street of the Paris Commune. Or what about the inscription on the back wall of this regrettably dark photo of the main staircase of Humboldt University:

Die Philosophen haben die Welt
nur verschieden interpretiert,
es kommt aber darauf an,
sie zu verändern

Not even attributed, you're meant to know it's from Marx's Theses on Feuerbach. Cool.  “The philosophers have only interpreted the world, in various ways. The point, however, is to change it.”

The building [1] stands on Bebelplatz, at the right of this panoramic view:-

On 10 May 1933, Bebelplatz made history in an inglorious manner. It was the site of the most notorious of the book burnings organized by the Nazis, in which important works of world literature were thrown into the flames.  Karl Marx's Theses on Feuerbach first amongst them no doubt. The 20,000 volumes burnt included Heinrich and Thomas Mann, Erich Kästner, Stefan Zweig, Heinrich Heine, and Kurt Tucholsky. Don't worry I haven’t heard of some of them either but you get the idea.  A monument to this outrage has been created in the square, consisting of a glass panel opening onto a white underground room with empty shelf space for (supposedly) all 20,000 volumes. A plaque bears an epigraph from an 1820 work by Heinrich Heine: Das war ein Vorspiel nur, dort wo man Bücher verbrennt, verbrennt man am Ende auch Menschen (That was only a prelude; where they burn books, they end burning people).

I say supposedly because my rough estimate of the shelf space was 6,000 volumes. My friend Vincent got a slightly higher figure but nowhere near 20,000. 

The books all came from the university building with the Karl Marx inscription. Though the inscription wasn’t there then of course. And we are told the ignorant thugs who did this deed were mainly “students”. I feel sorry for the librarian. I visualise him being charged with the duty of identifying all the offending volumes, which doubtless included many rare first editions. My sympathy might be misplaced of course, maybe he was a Nazi and revelled in the work. But I imagine not. A rector with Nazi tendencies, Eugen Fischer, was appointed in 1933 but I haven’t discovered if he was yet in place at the time of the book burning.

I want to comment on all those old buildings you see in the panoramic view of the square. They are, from the left, the State Opera, St. Hedwig's Cathedral straight ahead and the Humboldt University building. Now I haven't found an image of Bebelplatz in 1945 but here’s a fairly typical image of Berlin in that year.

So what I puzzle over is, when I was in an old church, the Humboldt University, various 19th century museum buildings, what was I actually in? A repaired pre-war building? Or a modern replica?  On a four day visit to Berlin I encountered a fair mix of modern buildings and old ones, but how old were the old ones really? 18th and 19th century? Or 1960’s? I came away without a feel for the answer to this question.  I've plenty more to say about Berlin but I'll stop here for now.

[1] Now known so far as I can tell as the old law library