From the Enlightenment to the end of the nineteenth century, France experienced political change and literary innovation which resulted in new definitions of the relationship between mankind and God. Current research in nineteenth century French literature has discovered a wealth of diverse and provocative topics within this humanist tradition precisely because it was a time of experimentation and change which gave birth to new viewpoints on everything from gender roles and sexuality to socialism and human rights. This dissertation delves into the evolution of an often overlooked element of French life which went hand in hand with social and intellectual innovation: religion and spirituality. Under the Catholic monarchy, France had traditionally relied on religion as the foundation for a collective morality. Enlightenment philosophy challenged traditional religious concepts and France's post-Revolutionary break with the Catholic Church encouraged intellectuals to continue exploring new notions of the divine. This dissertation focuses on a number of spiritual ideas put forward by various writers. While some, such as Chateaubriand, Ballanche and Lamennais famously advocated a return to Catholicism, others like Mme de Staël and Lamartine used their writings as a means for devising a new spiritual direction that would rely less on institutionalized religion and more on the conscience. Advancements in science and in the study of history ushered in a new awareness of the relationship between the past and the future which inspired scientifically minded intellectuals, such as Auguste Comte and Emile Zola, to consider themselves as part of a progressive succession of human beings more dominated by time and society than by any god. By shedding what they saw as outmoded conceptions of the universe, philosophers, poets and novelists alike moved to embrace a more progressive spiritual direction incorporating compassion, empathy and justice as sources for moral truths. These are concepts that have carried over into secular France today as citizens continue to focus on ethical concerns in political debates that touch on topics such as welfare programs, immigration, and secularism.