The paper argues that believing in the truth of scientific theories is important, and defends this idea against a type of agnostic view that says we can't know if theories are true. It shows that there isn't a big difference between believing in theories and believing in observations. It also says that being skeptical about scientific theories could be worse than believing in them. The paper uses an argument to support the idea that scientific realism, which involves believing in the truth of theories, is a good approach to science.