Knowledge of the existence of the external world

Locke agrees with Desacrtes' arguments made about the knowledge of ourselves and God but he is unique in his argument on sensitive knowledge. Locke views sensitive's knowledge problem to be the idea that the skeptic holds: if we only have acess to our own ideas then how do we even know a world out there exists? In response to the skeptic's feelings, Locke formulates three strategies. First, he wonders if anyone can deny the existence of the external world and simply states to not take the skeptic seriously. Second, he tells those whose belief is strong in the skeptic to continue to believe since we already know enough to help us get around in the world. Third, he creates a long and detailed argument based on inference to fidn truth in the claim that an external world exists. In this argument, he uses the example of a deaf person never knowing the sound of a French horn to explain that we cannot get any ideas without the organ appropriate for them. He also says that these ideas can be recieved only in certain situations.
-Chris Rehonic