The book exposes serious flaws in the reductionist assumptions of Mind and Matter of Naturalism and Constructivism, which underlie research and theorizing on cognition, language and action within current academic psychology. The author argued for alternative tenable assumptions about the relation between mental and material reality which, as a matter of principle, must be taken for granted, and be the point of departure for all further investigations into both reality and our descriptions of it. It is the intention to show that the assumptions and principles derived from the arguments in the book offer a consistent foundation for a science of psychology. Furthermore, it seems that they open up new and straightforward ways of dealing with key-issues of truth and intentionality, subjectivity and objectivity, of relevance to psychology, philosophy and the humanities.