Eleaticism is a philosophical school of thought that originated in ancient Greece, primarily associated with the philosopher Parmenides. It emphasizes the idea that reality is unchanging and that change and plurality are mere illusions. Parmenides argued that what truly exists is a singular, eternal, and unchanging substance, which he referred to as "Being." Another key figure in Eleaticism is Zeno of Elea, known for his paradoxes that challenge the notions of motion and plurality. His arguments aimed to demonstrate that our perceptions of change and multiplicity are contradictory, reinforcing the Eleatic belief in the unity and permanence of existence.