One Lump Or Two, Mister Hitler?

Whilst all 5 men lived in Vienna during 1913, there is no historical account of the time that factually clarifies that Hitler met Trotsky, or if Stalin knew Tito, or if Freud knew any of them at all. Maybe they never did but let's just imagine for a moment that they did. For the purpose of this book, the question now becomes - what on earth would they have found the time to talk about...