In Kant's metaphysics, he claims that the world of human experience (phenomena) is categorically different from things in themselves (noumena). He states that there is no reason to believe that the world as we experience it is the same as things are "in themselves." Doesn't the fact that the way we have experienced the world as human beings has led to evolutionary success reveal that while phenomena may not exactly duplicate noumena; it must certainly resemble it very much? The fact that we successfully manipulate the external world through our knowledge that comes from experience,seems to suggest that they way things are in themselves is very much like we experience them. Even to the extent that phenomena may give us a lot of information about how things are in themselves.