Starting from the remark that poetry and biography have simultaneously undergone a comparative decline during the last century, this article proposes to investigate some of the common causes of this double phenomenon in the history of literature. Apart from the often evoked ideological reasons sustaining a doctrine of literary theory that radically turned its back on the biographic approaches of the nineteenth century, this paper dwells at greater length on the fact that poets themselves have concurred to promote a dogma of impersonality, which has developed essentially in American and French academic criticism, and may well have severely uprooted poetry itself. The following diachronic study is an apology for reconsidering biographic approaches to poetry and literature as a means towards renewed exchanges between literary science and other scientific disciplines.