In the post-enlightenment Europe of the 19th century the highest authority was no longer the Church. Instead it was science. Thus was born racial anti-Semitism based on two disciplines regarded as science in their day - the 'scientific study of race' and the Social Darwinism of Herbert Spencer and Ernst Haeckel.
The dialogue between client and architect is about as intimate as any conversation you can have because when you're talking about building a house you're talking about dreams.