This rather shoddily produced book appears to have been thrown together rather quickly (note, among other things, the repetition on pp. 2 and 29 of the same quoted passage), and the material presented often left me wondering why this and not something else? For instance, chapter 2 contextualizes Bergson, but almost exclusively in terms of science. As the Bergson under examination is a philosopher, why are so few philosophers mentioned in this chapter? Guerlac is not a fool, and she has read Bergson carefully, but she has not taken the time to present her findings in a properly constructed scholarly framework. And her lapses are sometimes grotesque: in chapter 3, Kant is identified as an empiricist!
To cite some of Guerlac's less egregious errors, a passage on page 3 ascribed to Louis de Broglie was in fact written by Papanicolaou, and both that passage and the one following are inaccurately quoted. The block quotation on pp. 20 and 21 is not accurate. On page 27 the title of Darwin's most famous text is mangled, and the attempt to distinguish Lamarck's ideas (recently given new life) from Darwin's is bungled. The quotation in line 5 of page 28 is not from Bergson. (The suggestion that Bergson sets up intuition in opposition to science, set forth on this page, is wrong. Bergson saw intuition as a complement to the techniques proper to science.)
Too often, in the introductory chapters, Guerlac does not identify the Bergsonian work she quotes, contributing to a tendency widespread among philosophers and literary critics to view an author as standing outside of time. But thinkers do change over time, and it's important in a work of this sort to look carefully at when they said what.