There is only one way to make progress: through conjecture (guesses) and criticism. We create theories by rearranging, combining, altering, and adding to existing ideas with the intention of improving upon them. The role of experiment and observation is to choose between existing theories, not to be the source of new ones.
Experience is indeed essential to science, but it’s not the source from which theories are derived. Its main use is to choose between theories that have already been guessed.