Philosophy of religion is defined as "the philosophical examination of the central themes and concepts involved in religious traditions." It is distinct from religious philosophy, which examines problems within a particular belief system, and from theology, which examines religious concepts from a specific religious tradition's perspective. Philosophy of religion objectively evaluates the truth of religious worldviews and can be pursued by both believers and non-believers.
William L. Rowe characterized the philosophy of religion as "the critical examination of basic religious beliefs and concepts." It encompasses diverse beliefs about God, gods, demons, and spirits, religious experiences, science-religion interplay, good and evil, and religious perspectives on birth, history, and death. It also studies the ethical implications of religious commitments, the relationship between faith, reason, and tradition, and concepts of miracles, the sacred, revelation, mysticism, power, and salvation.
The term "philosophy of religion" gained widespread use in the West in the 19th century, though pre-modern philosophical works often combined religious and non-religious themes. Examples include the Hindu Upanishads, Daoist and Confucianist texts, and Buddhist texts. Greek philosophies like Pythagoreanism and Stoicism had religious elements, and medieval philosophy was influenced by the Abrahamic religions. Early modern philosophers like Hobbes, Locke, and Berkeley also addressed religious topics.
Philosophy of religion differs from theology because theology bases its reflections on religious convictions and is accountable to a specific authority, while philosophy grounds its arguments in timeless evidence. Some aspects of philosophy of religion have been considered part of metaphysics, particularly the concept of an unmoved mover in Aristotle's Metaphysics.
Religions differ in their conceptions of ultimate reality, its source, and its "Maximal Greatness." Concepts like Paul Tillich's "Ultimate Concern" and Rudolf Otto's "Idea of the Holy" reflect concerns about ultimate truth. A key difference is whether ultimate reality is perceived as a personal god or an impersonal reality. Western religions often embrace theism, while Eastern religions include both theistic and non-theistic views.
Philosophical positions on the existence of God include theism (monotheism, polytheism), agnosticism, and atheism.
Keith Yandell identifies three types of historical monotheism: Greek, Semitic, and Hindu. Greek monotheism posits a world that has always existed, without creationism or divine providence. Semitic monotheism believes in a God that created the world at a specific time and acts within it. Indian monotheism views the world as beginningless, with God's creative act sustaining it.
Aquinas presented five arguments for the existence of God, known as the quinque viae.
Eastern religions feature both theistic and non-theistic views of ultimate reality. Jainism posits a dualistic view of matter and multiple souls (jiva), independent of a supreme deity. Theravada Abhidharma Buddhism views reality as consisting of transitory phenomenal events (dharmas) and their relations.
Madhyamaka Buddhists, like Nagarjuna, consider ultimate reality as emptiness (shunyata), while Yogacara holds it to be vijñapti (mental phenomena). Adi Shankara's Advaita Vedanta presents a non-dualistic oneness (Brahman without qualities), where appearances, including persons and gods, are illusory (maya).
Taoism also offers non-theistic perspectives on ultimate reality (Tao). Xuanxue thinker Wang Bi argued that everything is rooted in Wu (non-being), while Guo Xiang proposed that the Tao's ultimate nature is "spontaneous self-production" (zi sheng) and "spontaneous self-transformation" (zi hua).
Traditionally, Jains and Buddhists did not deny the existence of limited deities but rejected the notion of an all-powerful creator God.
Religious traditions make epistemic, metaphysical, and ethical knowledge claims. Evidentialism asserts that a belief is rationally justified only with sufficient evidence. Many theists and non-theists agree on this principle but disagree on whether evidence for God exists.
William Kingdon Clifford argued, "It is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence." William James countered this in "The Will to Believe" (1896). Antony Flew and Michael Scriven support evidentialism, relying on the Ockhamist view that belief in X is unjustified without evidence. Modern Thomists also hold that there is evidence for belief in God.
Non-evidentialists, like fideists and reformed epistemologists, argue that religious belief is warranted without evidence. Alvin Plantinga views religious beliefs as "properly basic beliefs," not irrational even without support, provided they can be defended against objections. Properly basic beliefs include memories, sensations, and perceptions.
Plantinga argues that belief in God is a properly basic belief because there is a natural awareness of divinity within every human mind.
William James, in "The Will to Believe," justifies religious belief pragmatically, arguing that it is justified if a question is rationally undecidable and options are genuine and relevant. Religious belief is defensible due to its pragmatic value, even without rational evidence.
Contemporary epistemology of religion considers knowledge-how, practical skill, the impact of practical factors on knowing theism's truth, formal epistemology's probability theory, and social epistemology (testimony, disagreement).
A key topic is religious disagreement among individuals of equal epistemic parity, posing first-order (evidence directly applies to a religious proposition) and higher-order problems (rational assessment of first-order evidence). The Argument from nonbelief is an example of a first-order problem. Higher-order discussions address whether religious disagreement requires skepticism or changes in religious beliefs.
Religions use rational arguments but also rely on faith as confidence or trust in religious belief.
Models of faith include:
The affective model: faith as a feeling of trust.
The special knowledge model: faith as revealing religious truths (Reformed epistemology).
The belief model: faith as theoretical conviction.
Faith as a fiducial commitment: faith as trusting in God.
The practical doxastic venture model: faith as commitment to believe in a religious truth.
The non-doxastic venture model: faith as practical commitment without belief.
The hope model: faith as hoping.
Views on the relationship between faith and reason include compatibility (Aquinas) and independence/adversariality (Fideism). Aquinas posits that reason establishes religious truths, and faith accesses truths about the divine beyond human reason.
Kierkegaard advocated for a non-rational leap of faith. Wittgensteinian fideism sees religious language games as incommensurate with scientific language games, judged only by their own standards. Critics argue many religions make metaphysical claims.
New Atheist writers view religious and scientific claims as opposed, deeming religions false. Karl Barth rejected natural theology, stating that human reason is corrupt, and religious knowledge relies only on God's revelation (Neo-orthodoxy). D.Z. Phillips argues God is not intelligible through reason because God is not an empirical object. Brian Davies notes that such positions do not help resolve competing revelations among religions.
The compatibility of religious beliefs and science is an important topic, examined through historical interactions and conflicts, such as debates over evolution and creationism.
Models of interaction include:
Conflict thesis: constant conflict.
Independence model: separate domains.
Dialogue model: some overlap but remain separate.
Integration or unification model: natural theology and process theology.
The field also draws on the scientific study of religion by psychologists, sociologists, and cognitive scientists. Evolutionary theories view religion as adaptive or a by-product. Cognitive science of religion also offers theories.
Some argue evolutionary or cognitive theories undermine religious belief.
Interpreting religious experiences and their potential for knowledge is closely tied to knowledge and belief. These experiences are diverse and personally significant.
Key questions include: "What sort of information about what there is might religious experience provide, and how could one tell?"
Experiences can be interpreted veridically, neutrally, or as delusions. Monotheistic and non-monotheistic thinkers appeal to religious experiences as evidence for ultimate reality.
Richard Swinburne and William Alston compare religious experiences to everyday perceptions, suggesting they could logically be veridical unless there is reason to disbelieve them. Eleonore Stump and Matthew Benton advocate for an interpersonal epistemology enabling one to experience and know God relationally.
Brian Davies notes that objections include the deceptiveness of experience and the possibility of misidentification or hallucination. However, he argues that not all religious experiences can be disproven based on these objections.
C. B. Martin argues that without agreed-upon tests, religious experiences can only establish the reality of psychological states.
Naturalistic explanations, such as fear of death, suggestion, neurological anomalies, and socio-political power, are seen as undermining epistemic value. Some argue religious experiences are cognitive misattributions akin to hallucinations. A counter-position, supported by William L. Rowe, argues that bodily and mental interference from reliable perceptions of the physical world may not interfere with reliable perceptions of a spiritual world. William James takes a middle ground, stating that mystical experiences are authoritative for the individual but neither veridical nor delusive for the outside observer.
Religious experiences vary, including "subject/content" experiences (euphoric meditative states) and "subject/consciousness/object" experiences (perception of seeing a god). Experiences of theophany are described in ancient Mediterranean works and Indian texts like the Bhagavad Gita. The diversity and contradiction of religious experiences is used as an argument against their veridical nature.
In Western thought, religious experience has been described by Friedrich Schleiermacher, Rudolf Otto, and William James. Schleiermacher emphasizes the feeling of absolute dependence. Otto highlights the numinous as a non-rational, non-sensory experience with qualities of mystery, terror, and fascination. Rowe defines religious experience as sensing the immediate presence of the divine.
Rowe divides religious experiences into:
Experiences sensing the divine as distinct.
Mystical experiences sensing union with a divine presence.
Typologies also include:
Regenerative experiences: feelings of being reborn or radically changed.
Charismatic experiences: manifestation of special gifts or abilities.
Mystical experiences: ineffable, noetic, transient, and passive experiences.
Non-monotheistic religions report non-dual experiences of oneness, meditative states (samadhi), enlightenment in Buddhism, liberation in Hinduism, and kevala in Jainism.
The debate focuses on whether all religious cultures share common core mystical experiences (Perennialism) or if these experiences are socially and culturally constructed (Constructivism).
Walter Stace argues that all cultures share mystical experiences of oneness and "Pure Conscious Events." Ninian Smart posits that monistic experiences are universal. Perennialists distinguish between the experience and its post-experience interpretation.
Constructivists, like Steven T. Katz, argue that every mystical experience contains concepts or is shaped by religious ideas and culture. Conceptual schemes strongly shape experiences, precluding universal mystical experiences.
All religions promote certain values and moral ideas. Non-monotheistic Indian traditions find the highest Good in nirvana or moksha, while monotheistic traditions view God as the source of morality and heaven as the highest human good. Religions offer different conceptions of the source of evil and suffering.
Brian Davies outlines four possible theses on the relationship between morality and religion:
Morality requires religion (Kant).
Morality is included in religion.
Morality is pointless without religion.
Morality and religion are opposed (Lucretius, Bertrand Russell, Kierkegaard).
Monotheistic religions address the Euthyphro dilemma: "Is the pious loved by the gods because it is pious, or is it pious because it is loved by the gods?" Divine command theory states that what is moral is so because it is what God commands.
Another topic is the problem of free will and God's omniscience, which could lead to theological determinism. Positions include libertarianism and Predestination.
Belief in miracles is common. A miracle is an event inexplicable by rational or scientific means. The Resurrection of Jesus and the Miracles of Muhammad are examples.
David Hume defined a miracle as "a violation of the laws of nature" and argued against miracles, stating that the probability of a miracle not occurring is always greater than the probability that it has. He argues that it is unreasonable to believe in miracle testimonies because the regularity of natural laws is better supported. Hume does not claim miracles are impossible, only that belief in them is irrational.
Rowe identifies weaknesses in Hume's argument:
Indirect evidence beyond testimony exists.
Hume overestimates the weight given to past experience in supporting natural laws.
Another definition is the Epistemic theory of miracles (Spinoza, St. Augustine), which views miracles as transgressions of our current understanding of natural law. This theory argues that a miracle is only intelligible in relation to human opinions, and simply means events of which the natural cause cannot be explained by reference to any ordinary occurrence, either by us, or at any rate, by the writer and narrator of the miracle.
R.F. Holland defines miracles naturalistically as extraordinary and beneficial coincidences interpreted religiously.
Brian Davies notes that even if a miracle occurs, it may not prove divinity but could be due to unusual, powerful, non-divine agencies.
Religions propose theories affirming life after death and various postmortem existences. Belief in an immortal soul separate from the body is common (Plato, Descartes, Christianity, Indian philosophers), aligning with dualism in the mind-body problem. Belief must show that souls exist and survive death. A key issue is continuity of personal identity.
Bertrand Russell offers a scientific argument against the afterlife: mental life is bound up with brain structure and bodily energy; therefore, it is rational to suppose that mental life ceases when bodily life ceases.
J. M. E. McTaggart argues people have no scientific proof of the mind's dependency on the body. Rowe uses the analogy of being trapped in a room while depending on the windows to see the outside world. Even if the room ceases to exist, the person might continue to see, after death.
Buddhism affirms postmortem existence through rebirth but denies individual souls (anatta).
Christianity traditionally holds that life after death includes bodily resurrection. This view faces issues with personal continuity, possibly resulting in replicas rather than the same person. The constitution view asserts persons are constituted by their bodies and a "first-person perspective". Peter van Inwagen suggests that God removes the corpse and substitutes it with a replica to combat this discontinuity.
Discussions on the philosophy of the afterlife also involve near-death experiences, reincarnation research, and parapsychological events, hinging on naturalistic explanations versus other explanations.
The understanding of religious diversity and the plurality of religious views is a central concern. Yashovijaya, a Jain philosopher, defended a theory of Anekantavada which is often regarded as inclusivism.
Philosophical positions include exclusivism, inclusivism, pluralism, relativism, atheism/antireligion, and agnosticism.
Religious exclusivism claims only one religion is true, with salvation attainable only by its followers, which is the orthodox view of most monotheistic religions, though liberal and modernist trends may differ. Rowe outlines problems: a large portion of humanity is excluded from salvation, and virtuous people in other religions seem unfairly excluded.
Inclusivism posits that one's tradition has the whole truth, partially reflected in other traditions. Inclusivists may hold their religion as privileged but recognize fundamental truths in other religions, even granting salvation. Smart highlights genuine differences between religions.
Religious pluralism holds that all religions are equally valid responses to the divine and paths to transformation. John Hick promotes a noumenal sacred reality accessed by different religions, viewing all religions as true encounters with the divine, despite varied deities and conceptions. Rowe notes a similarity to Paul Tillich's concept of Being-itself.
Perennialism asserts that all religions share a core experience with variation in terms. Thinkers of the Traditionalist School and Neo-Vedanta have espoused this view.
Relativism, defended by Joseph Runzo, argues for henofideism: the truth of a religious worldview is relative to each community, with individual validity arising from experiences of a plurality of phenomenal divine realities. This preserves individual dignity by not reducing ideas and experiences to interpretations of the Real.
Skepticism and antireligion view religions as illusions serving psychological needs, as argued by Sigmund Freud. Don Cupitt, while disbelieving in metaphysical claims, practices religion with a "non-realist" perspective, viewing claims as human inventions to live by.
The meaningfulness of religious language has been central since the Vienna Circle and Logical Positivism, which deemed talk of God unverifiable and meaningless. Hume similarly viewed works lacking abstract reasoning or factual existence as sophistry.
Antony Flew questioned the validity of religious statements for lacking falsifiability. While popular in the 1950s and 60s, verificationism and falsifiability are now less widely held.
The problem with verificationism is that is seems to be self refuting, for it is a claim which does not seem to be supported by its own criterion.
Religious traditions use metaphor, negation, and analogy. The via negativa, defended by Maimonides, denies that positive statements about God are helpful. Similar approaches include Hindu Neti neti and Buddhist Madhyamaka.
Wittgenstein's theory of language games allows analogical religious language, even if words do not refer to everyday senses. Patrick Sherry notes that simply making sense of this language does not warrant ascribing terms to God, requiring connection to criteria used for conventional objects. Wittgenstein argues a religion's language game need not reflect literal reality but reflects practices and forms of life.
Following Wittgenstein, philosophers of religion, like Norman Malcolm, B. R. Tilghman, and D. Z. Phillips, use non-realism, seeing it as referring to forms of life. Realists argue that this subverts religious belief and intelligibility, undermining prayer and lacking normative ways to choose between religions.
Early analytic philosophy avoided philosophy of religion, dismissing the subject as metaphysics and meaningless but, after the collapse of logical positivism, leading philosophers introduced new problems and classical topics.
Plantinga, Mackie, and Flew debated the free will defense. Alston studied religious language. Adams explored faith and morality.
Analytic epistemology and metaphysics have formed the basis for theistic arguments, like those of reformed epistemologists. Analytic philosophy of religion also studies Wittgenstein and Kierkegaard.
Wittgensteinian contemplatives developed contemplative philosophy, interpreting Wittgenstein's remarks. Kai Nielsen labeled this "Wittgensteinian Fideism," which Wittgensteinians in the Swansea tradition rejected as a caricature.
Kai Nielsen and D.Z. Phillips became prominent philosophers on Wittgenstein's philosophy of religion and offered a way to respond to other hostile forms of analytic philosophy.