Feyerabend claims that what is perceived depends upon what is believed ; and he maintains that among really efficient alternative theories "each theory will possess its own experience, and there will be no overlap between these experiences". According to Feyerabend "scientific theories are ways of looking at the world; and their adoption affects our general beliefs and expectations, and thereby also our experiences...". Toulmin, Hanson, and Kuhn concur with this view. Toulmin claims that men who accept different "ideals" and "paradigms" (...) will see different phenomena. He thinks theories not only give significance to facts, but also determine what facts are for us at all. Like Feyerabend, Toulmin asserts that "we see the world through" our fundamental concepts of science "to such an extent that we forget what it would look like without them". Indeed, both Feyerabend and Toulmin would have previous thinkers "live in an observational world very different from our own". Kuhn expresses quite similar views. He feels that. (shrink)