Introduction to Metaphysics is an essay by French Philosopher Henri Bergson about the concept of reality initially published in 1903 and later included in his book The Creative Mind: Introduction to Metaphysics (1923). The essay challenges classical notions of reality, asserting that it is mistaken to think of it as a series of discrete states, but instead it is an ongoing fluid process that resists reductive analysis. Reality can only be grasped through intuition, which Bergson described as a process of “entering into” an object. Classical philosophy of Plato and Aristotle posited true reality as consisting of timeless substances, with process and change subordinated as accidental. Bergson's concept draws instead from the ontology of constant change as the essence of the universe, best summarized in Heraclitus' famous dictum that “no man ever steps in the same river twice”.   The essay contains two notable examples of the distinction. In the first, he posits that analysis may enable us to construct a model of a city from a composite of photographs taken from every possible angle, but that only intuition can give us the sense of dimension of walking through the city. The second is that numerous translations and commentaries on the components of a line in Homer will never duplicate the experience of the line in the poem itself. Introduction to Metaphysics stands as an important document in the emergence of process philosophy and serves as foundation to his three major works, Time and Free Will (1889), Matter and Memory (1896), and Creative Evolution (1907).