being

Being is a central notion in ontology, the branch of philosophy that studies what there is and what it means for something to exist. It contrasts with particular beings, or entities, and with the act or condition of existence itself. The questions “What is being?” and “Why is there something rather than nothing?” have generated diverse theories about the nature of reality, identity, and change. In some contexts, Being with a capital B is used to denote a more fundamental sense of existence beyond everyday objects.

Historically, early Greek thinkers distinguished between Being and beings. Parmenides argued that true Being is unchanging and indivisible, while Heraclitus emphasized becoming and flux. Aristotle advanced a comprehensive account of being through categories and substances, developing the idea of being qua being—the study of what it means to be in the most general sense. In the medieval period, Thomas Aquinas synthesized Aristotle with Christian theology, treating existence as something beings have and arguing for the primacy of a necessary being, God. In modern philosophy, figures such as Descartes and Kant challenged earlier certainties and shifted attention to the conditions for knowledge and the status of objects within experience.

Twentieth-century phenomenology and existentialism, especially Martin Heidegger, reframed Being as linked to human existence, meaning, authenticity, and mortality. Since then, various currents in analytic ontology, process philosophy, and debates over realism and anti-realism continue to probe what it means to be, how beings are categorized, and how language and science shape our understanding of Being.