To provide an accurate interpretation of the term "optimistic" in the context of paragraph four of "Dean Shostak and His Glass Armonica," I would need to analyze the paragraph itself. However, since I don't have access to specific texts, I can offer a general understanding of the word "optimistic."
In general, "optimistic" refers to a hopeful and positive outlook on the future or on a particular situation. If you can provide the content or context of paragraph four, I would be able to give a more specific interpretation regarding how optimism is presented in that part of the text.