During the course of Western intellectual history, many philosophers have grappled with the problem of how it is possible (or if indeed it is possible) for us [Page 780]to gain knowledge about the external world. A number of rival epistemological theories have been developed in response to this challenge, and until recently, the major contenders have possessed at least one feature in common—they have depicted knowers as passive absorbers of input from the external environment. These theories have given different names to this input, and they have given different accounts of what happens after it has been absorbed—and in some of these accounts, the mind of the knower is far from being passive. But crucially, at the initial stage of reception of the input, the ...