In the centuries that have passed since Descartes's famous statement, "I think, therefore I am," science has often overlooked emotions as a source of a person's true existence. Even modern neurology, until recently, tended to focus on the cognitive aspects of brain function, ignoring emotions. This attitude began to change with the publication of the book "Descartes' Error." Antonio Damasio challenged traditional ideas about the connection between emotions and rationality. In this highly engaging book, Damasio takes the reader on a journey of scientific discovery through a series of case studies, demonstrating what many of us have long suspected: emotions are not a luxury, but are essential for logical thinking and normal social behavior.