Chapter three analyses the period between 1650 and 1800. Many thinkers see The Enlightenment’ as intoxicated with ideas of reason, control and with building perfect knowledge, organizations and societies. I demonstrate that this view is exaggerated. The ravages of wars produced two opposed intellectual movements: on the one hand, natural law and rationalism whose adherents believed in certain knowledge and abstract schemes; on the other, thinking in terms of probabilities, which recognizes and accommodates uncertainty. Hume, Smith, Voltaire and Montesquieu saw the limits of human reason and foresight and made considerable room for uncertainty. Military thinkers cautioned that war is unpredictable and that systematic knowledge is a pipe dream. Uncertainty and unpredictability occupied the centre stage in European culture; in paintings, the picaresque novel and the popularity of gambling and betting. This era was much contested as three different world views established themselves: The idea that the world could be understood and predicted, the sense that it is entirely uncertain and a pragmatic world view that recognizes and accommodates uncertainty as a part of the world.