How far have we progressed in the search for truth? This unique human pursuit of good explanations has driven remarkable improvements in every field, from scientific understanding and technology to politics, ethical values, and human well-being.

Will progress stop, either with a catastrophe or by reaching completion – or will it continue indefinitely? In this profound and innovative book, David Deutsch explores the ultimate scope of our current understanding of things, enlisting the Infinite Hotel, supernovae, and the nature of optimism in order to instill in all of us a sense of wonder at what we have achieved – and the knowledge that this is just the beginning of humanity's infinite potential.