referent term.
             However, in the English language, "Hunger Drive" carries excess meaning: that which implies an underlying motivation to eat. Whereas there may be physical structures and chemical phenomena that trigger a desire to eat in the absence of food, there is no known physical apparatus that defines a "hunger drive." In this case, it becomes an invented term.
             3. "What did Littman mean when he wrote (Page 132, Paragraph 2), 'The variation in behavior in the face of identical inputs and the constancy of behavior in the face of varying inputs leads us beneath the skin of the organism . . . motivation is what is inside the organism that accounts for . . . variable and uniform behavior'?"
             A) Not all externally observable behavior is explainable by external phenomena: One person enjoys a particular film, and is seen to leave the theater praising it, while another detests it. Loud complaints fill the theater exit hallway. In this case, we cannot simply look at a person and say, "this is why they liked it," or vice versa.
             B) Because we cannot observe externally the causes of this behavior, we look "beneath the skin of the organism." That is, we search for internal causes for it. In doing so, one might invent a term, such as a 'negative personality' for the complainer. This may not actually exist inside the person, but it is much harder to prove or disprove, because it is not directly observable.
             C) The particular invented term used in this case is motivation. In reality, it may or may not exist within the person. Littman's hunch, as well as my own, is that it probably does not exist as they define it.
             4. "According to Littman (Page 133, Para 1), what is/are the consequence(s) of placing the burden of explaining behavior on fictional causal entities that allegedly exist inside the organism?"
             The cited paragraph does not state e...