Philosophy of religion is the philosophical examination of the central themes and concepts involved in religious traditions. It involves all the main areas of philosophy: metaphysics, epistemology, logic, ethics and value theory, the philosophy of language, philosophy of science, law, sociology, politics and history, according to a definition by Stanford Encyclopedia of Philosophy. The term covers an investigation into the religious significance of historical events and general features of the cosmos such as laws of nature, the emergence of conscious life and widespread testimony of religious significance.
Philosophy of religion is an ancient discipline, part of philosophy, studying the questions regarding religion, including the nature and existence of God, analysis of religious language and texts, the examination of religious experience and the relationship of religion and science.
Ralph Cudworth was the first to use the term philosophy of religion in English in the seventeenth century. He and his Cambridge University colleague Henry More wrote philosophical work with a specific focus on religion. Before that work, the Greco-Roman philosophy and the medieval philosophers in the west spoke about philosophical reflection on God, or gods, reason and faith, the soul and afterlife, but not as a sub-discipline called philosophy of religion.
Today, philosophy of religion is an intensely active area of scientific investigation and its importance is mainly attributed to the alternative beliefs in God, the sacred, the varieties of religious experience, the relation between science and religion, the challenge of non-religious philosophies and the nature and scope of good and evil. Philosophy of religion also analyzes fundamental questions such as the human place in the university or the nature and limits of human thought.
There are three main factors which influence the importance of philosophy of religion, for the overall development of philosophy. Philosophy of religion embraces social and personal practices, having a vast role in addressing people's actual values. It keeps a close relation with people, as a large percentage of world population is affected by religion. The extent of this field is another reason for its importance. Almost all areas of philosophy have been influenced by the philosophy of religion. Historical reasons are the third factor of relevance. History of philosophy is closely related with philosophy of religion, as both eastern and western philosophers have studied religious topics.
Although philosophers of religion are not theologians, they are interested in religious questions. What is god or what is the relationship between faith and reason? What is the relationship between morality and religion? What is the status of religious language? What is the reason to believe in miracles? A philosopher of religion is interested in understanding whether there are knowable and opinable bases with regards to religions' claims.
Probably the most fundamental question is what god is. Philosophers of religion have been manly interested in the western, monotheistic conception of god, which places only one god in the center of the religion. Monotheistic religions believe in the existence of only one god, which traditionally is described as a supernatural being with at least three main characteristics, omniscience, omnipotence and omnipresence. But, there are also polytheistic definitions of the concept god. Polytheism is the belief in more than one god. All polytheistic religions agree that many gods exist, but the responses to that belief are different. The impact of non-monotheistic traditions to the standard canon of English-speaking philosophy of religion has been growing. Thus, philosophies of Hinduism and Buddhism have become part of the western approach to the philosophy of religion.
The other relevant question for the philosophy of religion is the god's existence. Over the centuries, religion philosophers studied various arguments like Pascal's Wager, the ontological, the cosmological, the teleological, the moral arguments and the argument from religious experience. Pascal's Wager argument suggests that it is in interest of people to believe in god. The cosmological argument has two forms, modal and temporal, and suggests that the universe is created by a being who keeps it in existence. The teleological argument says that the universe was created by a being but with an exact purpose. The argument from religious experience says that personal religious experiences can prove the existence of God. The experience of people who say they have perceived God constitutes indirect evidence of God's existence even to those who have not had such experiences themselves.