Whitehead is very difficult and somewhat neglected thinker. Isabelle Stengers has succeeded in offering a systematic reading of his scientific as well as his theological arguments. The result is a crucial contribution to a metaphysics that reopen the question of what Whitehead had called the 'bifurcation of nature', that is, the unwarranted distinction between primary and secondary qualities. The result, according to this review, is a serious proposition for a second empiricism.