The book investigates the core question of why human prosperity has consistently increased over time despite recurring fears of collapse. Matt Ridley, a science writer with a background in zoology, utilizes a framework rooted in evolutionary biology and economic history to argue that human progress is driven by the unique capacity for exchange and specialization. He posits that the 'collective brain' formed by trade allows for the accumulation of knowledge and the continuous improvement of living standards.

The text is regarded as a provocative contribution to the debate on human progress, often cited for its optimistic synthesis of economic and biological principles. The work is noted for its accessible prose, though it remains a subject of intense discussion among specialists regarding the long-term sustainability of the growth models it proposes.