Sentence:  The traditional strategy of the South has been to expose the vices of the North , to <WSD>demonstrate</WSD> that the North possessed no superior virtue , to `` show the world that '' ( as James 's Christopher Newman said to his adversaries ) `` however bad I may be , you 're not quite the people to say it '' . 
Meaning of the word marked with <WSD> tags:  establish the validity of something, as by an example, explanation or experiment