Sentence:  But it <WSD>is</WSD> true that the therapist can sense , when he hears this stereotype , that there are at this moment many emotional determinants at work in it , a blurred babel of indistinct voices which have yet to become clearly delineated from one another . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)