Creative Evolution (French: L'Évolution créatrice) is a 1907 book by French philosopher Henri Bergson. Its English translation appeared in 1911. The book proposed a version of orthogenesis in place of Darwin's mechanism of evolution, suggesting that evolution is motivated by an élan vital, a "vital impetus" that can also be understood as humanity's natural creative impulse. The book was very popular in the early decades of the twentieth century. The book also developed concepts of time (offered in Bergson's earlier work) which significantly influenced modernist writers and thinkers such as Marcel Proust and Thomas Mann. For example, Bergson's term "duration" refers to a more individual, subjective experience of time, as opposed to mathematical, objectively measurable "clock time." In Creative Evolution, Bergson suggests that the experience of time as "duration" can best be understood through intuition. Harvard philosopher William James intended to write the introduction to the English translation of the book, but died in 1910 prior to its completion. The history of the evolution of life, incomplete as it yet is, already reveals to us how the intellect has been formed, by an uninterrupted progress, along a line which ascends through the vertebrate series up to man. It shows us in the faculty of understanding an appendage of the faculty of acting, a more and more precise, more and more complex and supple adaptation of the consciousness of living beings to the conditions of existence that are made for them.