Sentence:  Sessions devoted to `` Ethics and Foreign Policy Trends '' , `` Moral Principle and Political Judgment '' , `` Christian Ethics in the Cold War '' and related subjects proved to <WSD>be</WSD> much livelier under this procedure than if Catholics were merely talking to themselves . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)