Sentence:  She could not resist the opportunity `` of showing her superiority in argument over a man '' which she had remarked as one of the `` feminine follies '' of Sara Sullam ; and in her forthright way , Henrietta , who in her story of Sara had indicated her own unwillingness `` to think of men as the privileged '' and `` women as submissive and yielding '' , felt <WSD>obliged</WSD> to defend vigorously any statement of hers to which Morris Jastrow took the slightest exception - he objected to her stand on the Corbin affair , as well as on the radical reforms of Dr. Wise of Hebrew Union College - until once , in sheer desperation , he wrote that he had given up hope they would ever agree on anything . 
Meaning of the word marked with <WSD> tags:  under a moral obligation to do something