Books on Amazon
Conscious mind/Animal/Dennett: we will never know where to draw the line, where animals have no consciousness: trouts, rats? But this is just another aspect of the inevitable limitation of our knowledge. Such facts are in principle beyond our knowledge.
Thinking/animal/Dennett: Animals do have certain special "concepts": because they have their special methods to distinguish things - not a German sentence necessary to allocate contents to animals.
Darwins gefährliches Erbe Hamburg 1997
Spielarten des Geistes Gütersloh 1999