Sentence:  To derive Utopian communism from the Jerusalem Christian community of the apostolic age or from its medieval successors in spirit , the monastic communities , <WSD>is</WSD> with an appropriate shift of adjectives , misleading in the same way as to derive it from Plato 's Republic : 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)