* Explores everything from self-belief to climate change denial and the anti-Vaxx movement, navigating readers through the functions of doubt, from the everyday to the extreme. * Looks at how doubt is dispelled, how it can be 'weaponised', and how both the proliferation and absence of doubt can lead to harmful belief systems. * Features interviews with Nobel prize winners, former terrorists, world class athletes, famous artists and coaches to explore how doubt functions in the lives of transformational thinkers and figures of popular interest.