This is the third book in a trilogy starting with 'The Hand' and 'I Am', and the culmination of an argument running through nearly a thousand pages in total.
Perhaps the best way to approach the trilogy is by starting with two fundamental approaches to the study of Man. One is philosophy, which examines, say, self-consciousness, free will and personal identity without any reference to the historical facts of how mankind came to be the way it is, but as if Man had fallen out of the sky, so to speak. By contrast, the historical approach to Man is inescapably Darwinian, and often reductive: for all their brilliance, Matt Ridley and Steven Pinker are often crassly reductive in a way that makes philosophers uncomfortable, since they are trying to resolve philosophical problems with tools provided by science. It is not mere professional jealously that motivates the hostility of philosophers to evolutionary reductionists. It is the realisation that many fundamental aspects of Man simply cannot be accounted for scientifically.
Tallis sets himself the huge challenge of bringing the historical and philosophical approaches together. As an academic doctor, he is well placed to evaluate the claims of science about Man -- both their power and their limits --, and as a remarakle polymath, who has written brilliant and funny demolitions of the moronic reductivists in the field of literary theory, he has the philosophical sophisitication to make relevant distinctions.
"The Hand" is the least philosophical, and most historical, book, and may be skipped by those interested in the latter aspects of the argument. It is nonetheless a fascinating elaboration of the claim that it is the development of the hand as a tool for manipulating the external world that led to the distinctive self-awareness of Man. Tallis is aware that in explaining the escape of Man from animality, one must take take as a starting point an un-self-conscious animal. The leap to Man is a difference of kind, and not merely degree, according to Tallis, and this is where his philosophical acumen and refusal to compromise with scientism comes in handy.
The philosophical aspects of that self-awareness are developed in "I Am", which contains chapters on self-consciousness and personal identity that are hugely rigorous and original. Having read quite widely in the philosophical literature, I can recommend them to students as weighty contributions to those areas. The same goes for the middle chapters in "The Knowing Animal", which take the argument from illusion (sticks looking bent in water), which has been gathering dust in university libraries for decades, and reinvigorates it with new life. These chapters can only be described as inspired.
This is a demanding book, but all good philosophy books are. It is also clearly written with a very light touch, and much humour and insight. (Only the chapter on free will eluded my grasp, but that may well be my fault). Tallis is a champion of the general reader, as opposed to the academic orthodoxies, and he has given the general reader (as well as the specialist) a truly extraordinary book.