Materialism
Materialism is the philosophical belief that the world is made of material, and that there are no other types of entity (things). Everything is composed of material. Things that are not made of material, such as consciousness, are the result of actions by material. In other words, matter is the only real substance. Physicalism is a related term.
Especially, a materialist does not believe in supernatural entities. Many of history's materialists thinkers have found the idea of a spirit either meaningless or not scientifically proven. By definition, these thinkers are therefore also atheists, though not all atheists are materialists, and there have even been some historically important Materialist thinkers who believe in a Pantheist idea of God (such as Baruch Spinoza and Friedrich Engels).
Modern philosophical materialists extend the definition to include other basic entities proven by science, such as energy, forces, and the curvature of space. Matter and energy are known to be interchangeable, and much else, such as gravity, is caused by matter. However, the concept of matter is itself not entirely clear.
Other types of philosophy share some of the aims of materialism. Examples would include reductionism, logical positivism and empiricism.
The origin of materialism is in a type of Ancient Greek philosophy. Thales, Epicurus, and Lucretius are early materialist philosophers. The idea also appeared in other ancient cultures.
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Philosophical movements and positions