With the help of scholars coming from various disciplines (history of philosophy, philosophy of language, linguistic, lexicography), the present volume suggests various ways to circulate in Condillac's writings on language.

We intend to show in this book how, at the end of the nineteenth century, the russian scientist and anarchist P. Kropotkin (1842-1921) waged a fight against social-darwinism, which used darwinian's natural selection model in order to justify social inequality.

This book intends rather to highlight the nature of Foucault's archaeological approach, he refers himself to a "history of the order of things" and to a "thought of the Same", which classical knowledge focuses issues.

In hegelian french-speaking litterature, only partial studies about Iena's period are available. The present book attempts to consider the whole of hegelian thinking of this time, and to question its transformations, as well in the field of logic as in those of philosophy of nature or philosophy of spirit.