The idea that the universe might be built up exclusively from material atoms was scarcely new to the seventeenth century, but the mechanical philosophy that was so central to the rise of modern science helped change the theological stakes in dramatic ways. Natural philosophy and theology indeed became more entangled in this period than before or since. To the vast majority of natural philosophers (and most especially to Newton and his epigones), it was inconceivable “that an army of infinite small portions, or seeds unplaced, should have produced this order and beauty, without a divine marshal.” Recurrent struggles against "Naturalists," atheists, deists, Spinozists, “anti-Scripturalists,” and indifferentists were not the inevitable religious backlash against incipient "secular" science, not when pious natural philosophers were nearly as likely to find offense. Where Enlightenment deists pondered a universal and rational order superior to the supposed provincialism of Christianity, prompting even Biblical scholars to re-read the Scriptures in new modes, the burgeoning forms of scientific knowledge in the nineteenth century frustrated the search for unity. The epistemological focus of materialism shifted from celestial mechanics to the realm of life, while at the same time fueling forms of political radicalism scarcely seen before. Our task in this course is to skirt the edges of grander secularization theses and seek to understand more precisely how the categories of materialism and atheism have acquired their historical contents, from early to high modern times. Throughout the course we will cycle between more canonical Anglophone topics and topics touching more directly on Central and East European concerns. While the bulk of the course is devoted to intellectual history, in later sessions we will nonetheless linger on the broader social history of atheism as state religion, first in the Soviet case, and--assuming adequate student interest--further in the East Bloc. Lurking in the background will be the post-positivist historian's constant dilemma: how to account for the various naturalisms that have contributed to humanist interpretations of modernity.