This article highlights the mathematical structure of Henri Bergson’s method. While Bergson has been historically interpreted as an anti-scientific and irrationalist philosopher, he modeled his philosophical methodology on the infinitesimal calculus developed by Leibniz and Newton in the seventeenth century. His philosophy, then, rests on the science of number, at least from a methodological standpoint. By looking at how he conscripted key mathematical concepts into his philosophy, this article invites us to re-imagine Bergson’s place in the history of Western philosophy.