Dogs fill our hearts with love and our minds with wonder, but their emotional lives have remained unexplored since Darwin 125 years ago. Now in , controversial psychoanalyst Jeffrey Masson brilliantly navigates the rich inner landscape of "our best friends." As he guides readers through the surprising depth of canine emotional complexity, Jeffrey Masson draws from myth and literature, from scientific studies, and from the stories and observations of dog trainers and dog lovers around the world. But the stars of the book are the author's own three dogs whose delightful and mysterious behavior provides the way to exploring a wide range of subjects—from emotions like gratitude, compassion, loneliness, and disappointment to speculating what dogs dream of and how their powerful sense of smell shapes their perception of reality. As he sweeps aside old prejudices on animal behavior, Masson reaches into a rich universe of dog feeling to its essential core, their "master emotion": love. Like the dogs he loves, Masson's writing will capture the reader with its playful, mysterious, and serious sides. Its surprising insights provide a new dimension of understanding for dog owners everywhere.