Sentence:  Thus, it is urged, we identify which emotion one has by whether one has a belief that is <WSD>definatory</WSD> of that emotion (and which, depending on one's view, either causes or is “internally related” to the arousal): a belief that the situation is dangerous marks the emotion as fear, a belief that one has been wronged marks it as anger, and so on. 
Meaning of the word marked with <WSD> tags:  Defining or implying.