Our working assumption reads: Every mental property exhibited by a natural system can be exhibited by an artificial system, at least in principle. Is this true? The paper is in two parts. The first part is explicative: What do we mean by 'natural' or by 'artificial'? When are we ready to ascribe thinking to a system? We show that sometimes behavior is enough, sometimes underlying mechanisms are...
The criterion that pure natural science can only investigate objective phenomena which can be observed by independent observers sets certain limits to pure natural scientific understanding of brain functions. It excludes consciousness and feelings since these are only subjectively accessible and alternatives cannot be decided objectively. The limitations of brain research are discussed by...