Hooves click on the cobblestones, carriages rattle, there is a rustle, voices talk at once. You can’t make out what they’re saying, but that doesn’t matter. This exhibition also wants to get you in the mood for what kind of city it must have been that Moses Mendelssohn entered from the south through the Hallesches Tor in 1743 – only the smell of horse manure was wisely avoided. Mendelssohn was 14 and, according to legend, walked five days from Dessau to visit David Fränkel’s Talmud school in Berlin. That takes a lot of determination. Anyone who takes on something like...