Vaisheshika approaches reality as a rigorously structured plurality, grounded in eternal, indivisible atoms (anu or paramanu) and a finite set of fundamental categories. Where some systems seek a single underlying principle, Vaisheshika sees the world as composed of discrete substances, qualities, actions, universals, particularities, inherence, and, in later formulations, non-existence. These categories are not merely logical tools but are taken as mapping the real furniture of the universe. Atoms of earth, water, fire, and air combine to form gross objects, while other eternal substances such as space, time, soul, and mind are also affirmed as independently real. The resulting picture is a robust, external-world realism in which multiplicity and particularity are not appearances to be overcome but the very texture of what exists.

This stands in sharp contrast to schools such as Advaita Vedānta and many forms of Buddhism. Advaita regards the manifold world as māyā, an appearance of the one non-dual Brahman, whereas Vaisheshika insists that individual substances, atoms, selves, and even God possess genuine, irreducible reality. Buddhist traditions that emphasize emptiness or mind-only perspectives typically deny permanent substances and a lasting self, while Vaisheshika maintains eternal atoms and enduring souls with their own stable natures. Even when acknowledging impermanence at the level of composite things, it anchors that change in unchanging atomic and categorical foundations. Thus, where these other schools often dissolve the solidity of the world into consciousness, emptiness, or momentariness, Vaisheshika affirms enduring entities and their real causal relations.

Compared with other realist and dualist systems, Vaisheshika’s distinctiveness lies in its atomistic and categorial precision. Sāṃkhya explains the cosmos through the evolution of a single primordial prakṛti alongside a plurality of puruṣas, treating matter as a continuous, evolving substratum rather than atomic units; Vaisheshika instead posits discrete atoms and does not rely on a single material continuum. Nyāya, its closest ally, largely accepts this ontology but directs its energy toward logic and epistemology, while Vaisheshika concentrates on what ultimately exists and how it is classified. Mīmāṃsā and Jainism also uphold realism, yet Mīmāṃsā is more concerned with Vedic authority and dharma than with physical atomism, and Jainism’s pluralism and relativism differ from Vaisheshika’s commitment to fixed categories and determinate natures. In this way, Vaisheshika offers a vision of reality in which the many are not shadows of the One, nor fleeting constructions of mind, but stable, knowable constituents ordered within a carefully articulated metaphysical scheme.