The infinite multiplicity of existing life forms calls for equally multiple approaches to studying the living. However, no approach will ever be capable of exhausting the various perspectives required for research on life. This impossibility is not only given by the unmanageable task of establishing an infinitely multidisciplinary approach but also by the diverse and ever-changing subject matters that can potentially fall under the category of the living. This book is nevertheless an eort in that direction: acknowledging a multiplicity of ways in which life forms may be studied, and a diversity of disciplinary perspectives suited for this task.