Why did Frege introduce this distinction between the reference and sense of a singular term (or his proper name)?

Why did Frege introduce this distinction between the reference and sense of a singular term (or his proper name)?
Spring 2019 PHIL 303: Philosophy of Language Paper 1 Topic Answer the following two questions in paper format. The paper ought to be typed with MSWord in a 12 size font, double-spaced, and 4 to 8 pages long. No quotation is allowed. Due March 12 (Tue.), 3:40pm. Send Word files as email attachments to kakiba@vcu.edu. Late submission is subject to point deduction at the instructors discretion. Make sure to receive the instructors acknowledgment of receipt of your paper to avoid later disputes. Q. 1. Explain Freges theory of sense and reference. In particular: What is the reference of a singular term (or Freges proper name)? What is its sense? (Begin with reference.) Why did Frege introduce this distinction between the reference and sense of a singular term (or his proper name)? What was his argument? What is a reference of a linguistic expression in general? What is its sense? What is a reference of a sentence in particular? What is its sense? (You may also want to say the reference and the sense of a (one-place) predicate.) Q. 2. Explain Russells theory of definite descriptions. In particular: Spell out his theory in details, using the example, The present Queen of England is old. (You may use logical symbols.) How is Russells view about definite descriptions different from Freges? What puzzles did Russell try to solve, and how? General tips for writing a good philosophy paper: 1. The paper should be understandable to any reasonably intelligent reader who is not familiar with the topic of the paper. Do not assume any expert knowledge on the part of the reader. (However, you may use the notation of predicate logic.) 2. Use simple and concrete expressions. Be specific. Do not use words you are not confident using. Give examples. 3. Whenever you introduce a technical term, define it, or at least explain it. Give examples. (Examples always help.) 4. Write short and simply-structured sentences. Do not go on and on in a single sentence. Do not try to say more than one thing in a single sentence. Divide longer sentences into shorter ones. 5. When you finish the paper, read it again from the beginning to the end. Make sure that it satisfies 1-4 above. Use the spellchecker. Additional tips for writing a good paper in philosophy of language: 6. Make the use/mention distinction correctly. Are you talking about objects in the world, or are you talking about linguistic expressions? (E.g., Plato vs. Plato.) If you are talking about a linguistic expression, put it in quotes . Plato is a philosopher. Use. Plato is a five-lettered word. Mention. Plato is a singular term. Plato refers to Plato. Is a philosopher is a predicate. Being a philosopher is a property. Is a philosopher expresses the property being a philosopher. The present King of France is bald. The present King of France is bald is a sentence. The present King of France is bald is false. 7. Always beware of what linguistic expression you are talking about. For instance, are you talking about a singular term, a predicate, a sentence, or a linguistic expression in general? (E.g., the present King of France vs. The present King of France is bald.)