Sentence:  And Vickers launched forth into a tirade very different from his platform utterances. He spoke with extreme contempt of the dense <WSD>stupidity</WSD> exhibited on all occasions by the working classes. He said that if you wanted to do anything for them, you must rule them, not pamper them. Soft heartedness caused more harm than good. 
Meaning of the word marked with <WSD> tags:  The property of being stupid.