What constitutes our concept of numbers and makes it possible for us to work with them the way we do? Which mental faculties contribute to our grasp? What qualities do we share with other species, and which ones are specific to us? This book addresses these questions to reveal that language plays a crucial role in the development of systematic number concepts. It analyzes the relationship between numerical thinking and the human language faculty, providing psychological, linguistic, and philosophical perspectives on numbers, their evolution, and development in children.