Naturalism (philosophy)

Naturalism is a broad philosophical framework regarding the nature of reality. It suggests that only natural laws and forces operate within our universe.

This perspective holds that everything in existence can be explained through natural processes. It excludes the influence of supernatural factors, such as deities, spirits, or ghosts. Some philosophers define this as a form of monism. This means they believe reality consists of only one kind of substance. In this view, the cosmos is all that exists, has existed, or will ever exist. This idea is often contrasted with supernaturalism, which posits forces beyond the physical world.

Philosophers distinguish between different types of naturalism to clarify their specific claims. Metaphysical naturalism is a robust version of this belief. It asserts that the universe contains nothing outside of nature. This includes the rejection of any inherent purpose or design in the natural world, a concept known as dysteleology. Metaphysical naturalists believe that mass, energy, and chemical properties account for all of existence. In contrast, methodological naturalism is a more moderate approach. This is not a claim about what is true, but a way of conducting research. It is the assumption that natural causes should be used in scientific practice. A scientist using this method does not necessarily deny the existence of a god. They simply focus on observable, natural explanations to complete their work.

There are also important connections between naturalism and other philosophical systems. Many thinkers treat naturalism as being equivalent to physicalism or materialism. Materialism is a specific doctrine where everything is viewed as a product of matter. For example, the Epicureans believed the world resulted from atoms falling and swerving in a void. However, some philosophers like Paul Kurtz argued that nature is better described by material principles. These principles include mass and energy as accepted by the scientific community. Other thinkers, such as Immanuel Kant, took a different path. Kant rejected certain materialist positions but practiced a form of liberal naturalism. This shows that naturalism can take many different shapes depending on the thinker.

Naturalism has deep roots in both Western and Eastern traditions. In Western history, the earliest proponents were the pre-Socratic philosophers in ancient Greece. Groups like the Milesians, including Thales and Anaximenes, were called "the physikoi." This term means "natural philosophers" because they investigated natural causes.

They often excluded the role of gods from their explanations of the world. Another group, the atomists, included thinkers like Leucippus and Democritus. In the East, similar ideas appeared in Hindu philosophy. The Samkhya school, one of the oldest dualist schools, viewed nature, or Prakriti, as the primary cause of the universe. This school did not assume the existence of a personal god. Other traditions, like the Carvaka and Nyaya schools, also emerged in ancient India.

During the Age of Enlightenment, naturalism began to emerge again in the West. In the 17th and 18th centuries, philosophers like David Hume and Benedict Spinoza explored these ideas. Some thinkers during this era adhered to materialism, which was the dominant form of naturalism until the late 19th century. In the 19th century, German materialism became a major topic of debate. Scientists such as Ludwig Büchner, Jacob Moleschott, and Carl Vogt were central to this movement.

Later, philosophers like Friedrich Engels and Karl Marx developed versions of historical materialism. These thinkers attempted to apply naturalistic views to the study of history and society. The modern use of the term "naturalism" was further shaped by American philosophers in the 20th century, including John Dewey and Ernest Nagel.

In contemporary philosophy, metaphysical naturalism is widely embraced within the natural sciences. Many academic philosophers today defend naturalistic doctrines. One major reason for this is the "causal closure of the physical." This is the scientific doctrine that all physical effects can be explained by physical causes. This idea has been strengthened by the build-up of scientific evidence throughout the 20th century. While many people worldwide still hold religious or non-naturalistic views, naturalism remains a central pillar of analytic philosophy. Some modern thinkers, like Quentin Meillassoux, have even proposed "speculative materialism." This approach seeks to return to older ideas to strengthen classical materialist thought.

Naturalism relates to many different fields of study and ways of knowing. It suggests that science and philosophy are not always separate. Some philosophers argue they form a continuum, where scientific methods can be used to explore philosophy. This view was supported by thinkers like Willard Van Orman Quine and George Santayana. By using naturalistic methods, researchers attempt to understand the "human spirit" and other complex phenomena. They argue that even ideas, logic, and mathematics can be explained through physical accounts. Ultimately, naturalism invites us to look closely at the universe to find the answers within it.