Although the Enlightenment's deepest roots go way back to [Renaissance#ESTILOS#1] humanism, its most immediate origins were to be found in 17th century Rationalism and in the rapid development of Natural Sciences, technology and investigation. It had a major impact on the culture, art and social forms of the time, and represented the most important European spiritual movement of the 18th century, influencing the political development of the century, giving it the name of the Age of Enlightenment. The Enlightenment's ideal was Nature dominated by Reason, which acted as a force to transform reality. Reason, criticism, freedom, religious tolerance and so on promoted peace and general prosperity. Its conception of the world, which was quickly assimilated by the bourgeoisie, was the most important ideological factor in the [French Revolution#contexto_enS#4]. Great urban centres, academies and universities were responsible for spreading the ideologies of the Enlightenment. "The Encyclopaedia", compiled by d'Alembert and Diderot in 1751, was the movement's key work because it brought together all the knowledge of the period from the Enlightened point of view. The philosophical and politico-economic theories of figures such as Rousseau and Kant or the Spaniards Jovellanos and Campomanes laid the foundations of the Enlightenment's ideology which was then applied to different fields such as philosophy, economics, art and politics.