This dissertation attempts to determine the intellectual, cultural, and social contributions of the European Freemasons who corresponded with, traveled to, or lived and worked in Russia. My study is based on the assumption that eighteenth-century Freemasonry was one of the structures through which the ideas about nature, social order, and science contributed to the formation of a public sphere. Despite Freemasonry's well established presence and, as I argue, instrumental influence on Russia, no academic study along the lines of contextual intellectual history has been undertaken for the study of the transmission of ideas between the European and Russian lodges. Freemasonry, an institution that found response and operated in both European and Russian contexts, provides a unique vantage point for a reconstruction of the intellectual milieu of the society, within which people discussed, disputed, and put into practice ideas and ideals of the Enlightenment. Freemasons in Russia "worked" to adapt various Western models to fit the Russian developmental needs. This fusion of different traditions and concepts is the most original aspect of the Russian movement. In my analysis of several interconnected themes---the creation of a public sphere, Westernization, transmission of ideas, and the transition from the Enlightenment to Romanticism---I organize the chapters of this dissertation around two most important transformations: of Russia and of the Enlightenment. During the course of the century, Freemasons in Russia departed from the original cosmopolitanism of the Enlightenment, chose different forms of Freemasonry, and gradually became more involved with in the concept of Russia as a separate national entity. By the end of the eighteenth century, while being closely allied with the intellectual and educational strivings of the Enlightenment, they began producing their own negations of some Enlightenment ideas, providing a transition to the sentimentalism.