Sentence:  His various aesthetic postulates remain as <WSD>landmarks</WSD> of a house divided against itself : Supra Expressionism , Neo Paganism , Neo Classicism , Neo Romanticism , Neo Jazz , Neo Ecclesiasticism , Neo Popularism , and most recently , Post Serialism - all competing with each other within one composer ! 
Meaning of the word marked with <WSD> tags:  an event marking a unique or important historical change of course or one on which important developments depend