Any ape can reach for a banana, but only humans can reach for the stars. Apes live, contend, breed and die in forests — end of story. Humans write, investigate, create and quest. We splice genes, split atoms, launch rockets. We peer into the heart of the Big Bang and delve deeply into the digits of pi."

This extraordinary run of prose is a wonderful example of how world famous neuroscientist Professor V.S. Ramachandran unlocks the mystery of human nature in his new book, The Tell-Tale Brain, in which he explains why humans can be in touch with the divine, while being at the same time very much of this Earth.

He delights in mixing the details of the biology of the brain with the philosophical challenges of what makes the human brain different from that of any other animal. Despite many sections of the book going well beyond any lay reader's working knowledge of the brain and leaving even the intelligent amateur struggling to sort out all the different lobes and insula, it is hard to be angry with an author who engagingly remarks "it is difficult to talk about the brain without waxing lyrical".

Ramachandran was born and brought up in Chennai in India, and achieved great academic glory, getting his PhD from Cambridge, working on how the brain handles visual perception, although he also became famous for deceptively simple experiments in behavioral neurology, which had profound implications. Later he became Director of Neurosciences and Psychology at the University of California, and was elected to fellowships at All Souls, Oxford, and the Royal Institution in London.

Dramatic evolution

When trying to define how mankind separated itself from the rest of the animal kingdom, Ramachandran argues that it is a fallacy that lots of gradual and small changes can only bring about gradual and incremental results. He dismisses this as linear thinking, and points to how the dramatic and fast changes of "phase transitions" happen all the time in nature. A block of ice will be a block of ice even as it warms up through 20 degrees, to 21 degrees, and on through to 31 degrees, but suddenly at 32 degrees, there is an abrupt and dramatic change as the whole block starts to melt as the crystalline structure decoheres.

Ramachandran argues that a similar event happened in the evolution of homo sapiens, for whom for millennia natural section had tinkered piecemeal with small changes here and there, and the results were simply apes who were slightly better at wielding sticks, social scheming, and remembering things, but not much more than that.

But then about 150,000 years ago, an explosive development of certain key brain structures and functions happened, which gave homo sapiens a mental phase transition. All the old bits and pieces were still there, but they combined to offer mankind full-fledged human language, artistic and religious sensibilities and consciousness and self-awareness. Within the space of 30,000 years humans began to build their own shelters, stitch furs and hides into garments, create shell jewellery and rock paintings, and carve flutes out of bones. "We had more or less finished with genetic evolution," says Ramachandran, "but had embarked on a much (much!) faster paced form of evolution that acted not on genes but on culture."

Ramachandran is modest about his ideas, despite their profound impact. He is anxious that much of what he puts forward will need to be tested and he hopes that this will lead on to better understanding, and more coherent theory in the future. As he illustrates it: today we are at the same stage for neuroscience that chemistry was in the 19th century. We are discovering the basic elements and grouping them into categories, but we are nowhere near having found the equivalent of the periodic table, and atomic theory is far beyond our present imagination.

The goal of The Tell-Tale Brain is to come up with a new framework to explain the self and its maladies. Ramachandran puts forward the notion that we do not understand how we balance between our inner selves and the world outside, while maintaining our privacy. He suggests that many types of mental illness may result from disorders in this equilibrium, and that understanding this might may pave the way not only for solving the abstract (philosophical) problem of the self at a theoretical level, but also for treating mental illness.

The Tell-Tale Brain: A Neuroscientist's Quest for What Makes Us HumanBy V.S. Ramachandran, Random House India, 357 pages, Rs499