<p>The main theme of the book is to defend a non-reductionist understanding of organisms through the concept of agency: organisms are agents of their own evolution. Their nature includes adaptation (understood here actively, through interpretation of the environment), self-organization, metabolism, teleology, self-reference, and self-expression. The book aspires to intervene in today’s frequent debates about agency as a fundamental characteristic of the living. These debates are taking place not only in philosophy but also in theoretical and evolutionary biology, disciplines increasingly connected to empirical observations (e.g. epigenetic inheritance).</p>