Democritus's particle theory states that each organism in the universe is made up of particles so minuscule that nothing smaller is possible. Democritus regarded those particles, commonly known as atoms, as unchangeable and indestructible. He also argued that some particles possess different characteristics, which explains the various types of matter throughout the universe.
Democritus, along with Leucippus and Epicurus, proposed the earliest views on the shapes and connectivity of atoms. He believed that atoms are always moving, differ in size, shape and temperature and are invisible. These men reasoned that the solidness of the material corresponded to the shape of the atoms involved. According to the Robinson Library, Democritus opposed the empirical idea that spirits, gods and demons controlled nature.
The theory of evolution used aspects of Democritus's particle theory as an argument. He always believed that there are factual and realistic reasons why the universe exists. Democritus received a lot of criticism publicly and from fellow scholars for his reasoning on the universe's creation. A valid and often used argument questioned the existence of atoms if they are not visible. The idea behind science is to have factual proof, while belief is having faith in that which cannot be seen. Therefore, some believe that this scientific belief is arguably hypocritical.