Sentence:  That this abandonment takes place on a stage , during an ' artistic ' performance , is enough to associate Jacoby with art , and to bring down upon him the punishment for art ; that is , he is suspect , guilty , punishable , as <WSD>is</WSD> anyone in Mann 's stories who produces illusion , and this is true even though the constant elements of the artist nature , technique , magic , guilt and suffering , are divided in this story between Jacoby and La^utner . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)