Sentence:  The displacement ( at least to a considerable extent ) of the ethical jurisprudence of the seventeenth and eighteenth centuries by positivism reshaped both international law <WSD>theory</WSD> and doctrine . 
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