Monism is a philosophical viewpoint that posits that all things in the universe are interconnected and originate from a single substance or reality. This perspective contrasts with dualism, which divides existence into two distinct categories, such as mind and body. Monism suggests that everything, including physical and mental phenomena, is part of a unified whole. In monistic thought, the distinction between different entities is often seen as an illusion. This idea can be found in various traditions, including Buddhism and Spinoza's philosophy, where the emphasis is on the oneness of existence and the interdependence of all things.