question: was there as much of a coherent ideology behind art deco as there was behind modernism? and if so what was it?
Art Deco is a style not an ideology like Modernism.
The term “Art Deco” comes from the Exposition Internationale des Arts Décoratifs et Industriels Modernes (International Exposition of Modern Industrial and Decorative Arts), the World’s fair held in Paris, France from April to October 1925. It was derived by shortening the words “Arts Décoratifs” in the title of the exposition.