The mental capacities of the human mind far outstrip those of other animals. Our imaginations and creativity have produced art, music, and literature; built bridges and cathedrals; enabled us to probe distant galaxies, and to ponder the meaning of our existence. When our minds become disordered, they can also take us to the depths of despair. What makes the human brain unique, and able to generate such a rich mental life?

In this book, John Parrington draws on the latest research on the human brain to show how it differs strikingly from those of other animals in its structure and function at a molecular and cellular level. And he argues that this 'shift', enlarging the brain, giving it greater flexibility and enabling higher functions such as imagination, was driven by tool use, but especially by the development of one remarkable tool - language.