The author holds the view that only systems or organisms with language can be conscious. This is just the beggining of where I think he is mistaken. He analyzes various studies supporting some kind of animal cognition and consciousness, but dismises it all as explainable by some kind of unconscious conditioning or learning. He also proposes a cortex-hippocampus system, that gives humans, the only conscious being in his view, his superiority over animals. Now lets see how we can critique these views:
There is no evidence of a special cortico-hippocampal system in humans, difering substancially, neurochemichaly or otherwise, from say, chimpanzees, higher apes, or large brained mammals.
The author view implies that aphasics, those with hippocampal lesions, autistic children, and humans without language should be unconcious. This is clearly not the case. And for that matter, hippocampal lesioned humans can speak.
Animals that can perfom complicated working memory tasks, or attentional tasks,or self-recognition tests, that in humans require consciousness, are performed by "unconscious learners" with ease.
Pre-linguistic infants are also out of the consciousness elitism.
Also, humans before language evolved were all unconscious, wich dosnt seem probable, because of the gradual evolutiion of cortical and whole brain organization.
Now, just because I find the authors view flawed, it does not mean it is a bad book. Quite the countrary, it is exiting, interesting, and full of insight. I recomend it to all those interested in consciousness studies, especially in the evolution of consciousness, and animal intelligence. There are a bunch of points that I agree with too, so maybe my review was a bit pessimistic. But who pays attention to criticism? Read for yourself and judge yourself. You might end up agreeing, and well, that can not hurt anybody.