Philosophy of Religion
The actual term "philosophy of religion" is itself a modern addition to the philosophical lexicon, being used sparingly in early modern times. One of the first occurrences in the English language can be found in the work of the Cambridge Platonist Ralph Cudworth (1617–1688), while toward the end of the eighteenth century the term Religionsphilosophie became part of an accepted terminology used by German-speaking philosophers. At this time, many thinkers sought to replace the previous idea of a "natural religion" with a "philosophy of religion," since the latter notion was deemed to bequeath a much more rigorous method of discovering truths about the nature and origin of religion. This conception of the subject received lucid exposition in Immanuel Kant's (1724–1804) Religion within the Limits of Reason Alone (1793). Building on his earlier demolition of the traditional proofs for the existence of God in the Critique of Pure Reason (1781, revised in 1787), Kant argues in this work that religion is not a matter of theoretical cognition but of moral disposition. Hence religion is to be understood as a moral outlook to observe all duties as divine commands.
By the early decades of the nineteenth century, however, the term had already changed its meaning. In Georg Wilhelm Friedrich Hegel's (1770–1831) famous Lectures on the Philosophy of Religion (1821–1831) the subject is defined as the study of the manner and ways in which God is represented in religious consciousness. What is interesting about the respective projects of Kant and Hegel is the gulf that separated their respective accounts of philosophical theology from more orthodox religious doctrines. Indeed such was the extent of these differences that, despite their very best intentions, many of their theories eventually lent themselves to forms of antitheistic skepticism. Given this, it is unsurprising that Kant and Hegel are followed by resolutely atheistic thinkers of whom Arthur Schopenhauer (1788–1860), Ludwig Feuerbach (1804–1872), Karl Marx (1818–1883), Friedrich Nietzsche (1844–1900), and Sigmund Freud (1856–1939) are the most prominent. Although the general drift toward atheism in Continental thought might be said to have been countered by the writings of thinkers such as Friedrich Schleiermacher (1768–1834) and Søren Kierkegaard (1813–1855), the inheritance of nontheistic philosophers who followed in the wake of Kant and Hegel was subsequently refined and extended in the twentieth century by figures such as Jean-Paul Sartre (1905–1980) and Martin Heidegger (1889–1976), whose own work yet further entrenched philosophical atheism in many areas of French-and German-speaking thought. In many ways, early-twenty-first-century philosophers of religion who look to these various traditions of so-called Continental philosophy can be said to explore and clarify questions about the nature and meaning of religion that go back to the very different legacies of Kant, Hegel, Nietzsche, and Freud.
Early-twenty-first-century English-speaking philosophers of religion, however, be they of theistic, agnostic, or atheistic orientation, can be said to adopt a quite different outlook on their subject. In opposition to Continental thought, they tend to characterize philosophy of religion as the critical analysis of certain concepts and issues deemed central to the study of monotheistic Western religions. An important stimulus to their work can be found in the trenchant critique of religion advanced by David Hume (1711–1776), specifically in his Natural History of Religion (1757) and Dialogues Concerning Natural Religion (1779, but first written in the 1750s). For Hume the arguments of what he terms "natural religion" do not establish the existence of any deity that could be the proper object of religious belief. If revelation cannot be authenticated in any way conducive to reason, then religious beliefs can be deemed to have natural causes. Central to Hume's argument in the Natural History of Religion is the contention that the very origin of religious belief is to be found in numerous human pathologies that derive from a fear of the unknown. Hume's views have been typically regarded as providing a dialectical framework for modern English-speaking philosophy of religion. Accordingly, those who adhere to the claims of natural theology and traditional religion are supposed to address his intricate critique of their position, while those enamored of atheism invariably look to Hume's works as providing a paradigm for how to demonstrate that the claims of the theistic tradition are but a set of philosophical fictions.