David Hume Notwithstanding, Abstract Thought in Animals Is a Myth

Atheist mathematician Jeffrey Shallit:

There is... evidence for abstract thought in animals other than people. Evidence exists for dogs, baboons, and crows, to name just three examples. Of course, all these examples are debatable (although I find these and others pretty convincing), and will likely continue to be debated until we know more about how abstract concepts are represented and processed in brains. Nevertheless it is pretty obvious that this is a question that, at least in principle...