Sentence:  To guard against the tyranny of a numerical majority , Calhoun developed his <WSD>theory</WSD> of `` concurrent majority '' , which , he said , `` by giving to each portion of the community which may be unequally affected by the action of government , a negative on the others , prevents all partial or local legislation '' . 
Meaning of the word marked with <WSD> tags:  a well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena