• Why do you think Kuhn calls factual novelties “discoveries” and theoretic novelties “inventions” (pp. 52-53)?

• Kuhn later says that the case of oxygen prompts the “impossible suggestion” that Priestley first discovered it and Lavoisier then invented it—what about the case suggests this description (pp. 53-56)? (The later comment is on p. 66.)

• How is the discovery of X-rays like and, especially, how is it different from the discovery of oxygen (pp. 57-61)?

• What is shown by the example of the Leyden jar (pp. 61-62)?

• What features do the phenomena described by Bruner and Postman share with scientific discovery (pp. 62-64)?

• Why does Kuhn think normal science is effective in producing novelty (pp. 64-65)?