Henri Bergson's philosophy is centered on forming a concept of lived time or durée, which he saw as a process of continuous variation and flux. He believed that the study of time should be the foundation of philosophy. By studying time, we find an integration of concrete, infinite, qualitative multiplicity within consciousness that we should use to understand the essence of reality. I show that his insights into the reality of duration come directly from a metaphysical or phenomenological interpretation of (...) integral and differential calculus. Drawing on the recently published lectures from 1902–1905, I show how An Introduction to Metaphysics schematizes the methodology of Matter and Memory and Time and Free Will by means of this mathematical analogy. To Bergson, the concepts of calculus are not mere metaphors; they unleash certain metaphysical implications that problematize the mind's relation to movement, life, consciousness, time, and consequently, reality itself. (shrink)