Answering the question 'what is Enlightenment?' Kant famously urged men and women above all to 'have the courage to use your own understanding'. Robertson shows how the thinkers of the Enlightenment did just that, seeking a rounded understanding of humanity in which reason was balanced with emotion and sensibility. His book goes behind the controversies about the Enlightenment to return to its original texts and to show that above all it sought to increase human happiness in this world by promoting scientific inquiry and reasoned argument. His book overturns many received opinions - for example, that enlightenment necessarily implied hostility to religion (though it did challenge the authority traditionally assumed by the Churches). It is a master-class in 'big picture' history, about one of the foundational epochs of modern times.