Who is Carnap from The Logic of Scientific Discovery and what is their importance?

Carnap promotes the value of both inductive and deductive logic in science. He agrees with Popper that there is a difference between justification and discovery, but takes a different approach to understanding that distinction. Carnap claims that all philosophical investigations speak of the forms of speech, thus, the logic of science must investigate scientific language and its forms. He calls sentences which represent experiences "protocol sentences" in distinguishing between empirical and theoretical laws. Therefore, scientific sentences can only be compared with other scientific sentences, not with experiences. Still he is translating experiences into forms of speech, retaining a psychologistic approach. He claims that science should stop at the point of perceptions, even though intersubjective testing is difficult at these points.