The author argues that Plantinga's Proper Function and Evolutionary arguments fail against liberal naturalism defined in a broad sense as the view that 'here aren't any supernatural beings'. The former argument can be interpreted in at least three ways: deductively, inductively and theistically. None of these, however, is successful. The latter argument suffers from several deficiencies of which two major ones are: (1) The unlikelihood of the reliability of our cognitive faculties, given (liberal) naturalism and (varieties of) evolutionism, is not shown. (2) Agnosticism with respect to the likelihood of our cognitive reliability is insufficient to establish the self-defeating character of naturalistic evolutionism, unless it is also shown that the belief in this reliability lacks an independent warrant. The last condition has been neglected by Plantinga.