5. An elementary proposition is a truth-function of itself.
Ludwig reconciles with his siblings. They ask him to help Paul Engelmann build a house for sister Gretl on the Kundmanngasse. Ludwig is to design the windows, locks, and radiators. But his name is on the plans, he does more. He reduces a contractor to tears with his perfectionistic carping. Completion is delayed so that he can raise a ceiling 3 centimeters to get proportions exactly right.

From outside the house is a bare stucco almost cube; inside it is all polished dark stone floors, pale ochre walls and ceilings. Carpets, chandeliers, curtains are kept out; metal window casements are left unpainted; rooms are lit with naked light bulbs.

Sister Hermine: "I always knew that I neither wanted to nor could live in it myself. I even had to overcome a faint inner opposition to this 'house embodied logic' as I called it, to this perfection and monumentality."

Ludwig: "The house I built for Gretl is the product of a decidedly sensitive ear and good manners, an expression of great understanding (of a culture, etc.). But primordial life, wild life striving to erupt into the open - that is lacking. And so you could say it isn't healthy."