From Randall Gray
The editorial prefacing your article on thought suggests that our ability to think in many ways – “from idle reverie to determined problem-solving” – may be what defines us as human (21 September, p 5).
But other animals are known to solve multi-stage problems, such as ravens. Doubting purposeful thought in all non-human organisms seems to be an arbitrary distinction. A bird may well not think in the way we do, but then not all people think the same way either.
Grove, Tasmania, Australia
