Naturalism is a worldview that asserts that the universe is a closed system in which matter and energy are the only realities. This perspective rules out the existence of any supernatural beings including God. According to naturalism, the world operates according to natural laws in which there are a series of cause and effects. Because the universe operates according to natural processes there are no miracles or events that have any supernatural cause. Thus, everything in the universe is subject to scientific study and verification. Naturalism would be consistent with materialism and monism in which all of reality is inherently connected to the physical realm. Naturalism disagrees with dualism and its assertion that reality is made up of two distinct substances—the material and the immaterial. This rejection of dualism means that naturalists do not believe that people have an immortal soul that can survive physical death. For naturalists, the present life of a person is the only life he or she will ever have. There are no past lives to due to reincarnation nor is there a future life in some state of bliss or torment.
Because naturalism rejects any concept of the supernatural this view is intrinsically linked with atheism, the belief that there is no God. Naturalism also usually leads to the rejection of moral absolutes since there is no divine being or law that determines standards for right and wrong. Thus, naturalism often leads to ethical relativism in which individuals and societies are free to determine their standards for right and wrong.
David Hume was a key figure in laying a philosophical basis for naturalism. He refuted the idea of miracles claiming that testimonies of miracles were most likely false reports. Charles Darwin’s theory of evolution was also important in that it offered a purely naturalistic explanation of origins. Naturalism is well-represented today and is the prevailing worldview in the academic and scientific communities of the West.
Christianity and Philosophy
Christianity is often viewed as one of the world’s major religions, but Christianity also offers a philosophy of life that has greatly influenced Western society for nearly two thousand years. Thus, to ignore Christianity in the study of philosophy is a great mistake.
Christianity was founded by Jesus of Nazareth (c. 4 B.C.–A.D. 33) who is famous for his teachings, miracles, death, and resurrection from the dead. The Christian movement was furthered by Paul of Tarsus who through his missionary travels took Christianity to many areas of the known world. Much of Judaism is found within Christianity such as beliefs in one God and a linear view of history in which God will eventually triumph over evil and establish a new heavens and a new earth. Christianity differs from Judaism, though, in its assertion that Jesus was the divine Son of God and the Messiah of Israel. Christianity also uniquely asserts that Jesus’ death on the cross was a substitutionary atonement for the sins of the world.
While Christianity itself is rooted firmly in the life of Jesus and the writings of both the Old and New Testaments, this religion has often intersected with the discipline of philosophy. Some early Christians rejected any merger between Christianity and philosophy. For example, the church father, Tertullian, (160–225) declared, “What has Athens to do with Jerusalem?” to show that Greek philosophy has nothing to do with Christianity. Other church fathers, though, were positive toward the value of philosophy. Justin Martyr (c. 100–165), for example believed that God scattered “the seeds of his Logos [Word]” throughout the world before sending Jesus. Thus, Justin believed that the world had experienced some truths of God through philosophy even before Jesus came into the world. Justin also held that Christianity brought to fulfillment some of the insights of classical philosophy including that of Platonism. Another church father, Clement of Alexandria (c. 150–215), asserted that God gave philosophy to the Greeks in order to prepare them for the coming of Christ. Thus, Greek philosophy was not a competing worldview. According to Clement, Jesus was the fulfillment of philosophy.
The influential theologian and philosopher, Augustine of Hippo, also viewed philosophy favorably. Although acknowledging that some areas of philosophy were not valuable, he believed that there was no reason why Christians should not adopt the good things of philosophy and use them in their Christian walk and witness. Augustine, himself, relied upon several major teachings of Plato and Plotinus, the founder of Neo-Platonism. Augustine credited Neo-Platonism for helping him reject the Manichean view that all reality was material. Augustine also adopted Plato’s theory of forms, placing these “forms” in the mind of God. In fact, until the thirteenth century, the Christian church often looked favorably upon the ideas of Plato. During the thirteenth century, though, Christian scholars rediscovered the writings of Aristotle. Thomas Aquinas (1225–74), for example, attempted a merger between Aristotelian ideas and Christianity. Aquinas used Aristotle’s concept of a Prime Mover who caused all motion in the universe as support for his idea that the Christian God must have created and designed the universe.