Chapter. 1. IntroductionChapter. 2. Energy Conversion: How Life Makes a LivingChapter. 3. The puzzle of cooperationChapter. 4. A Thumbnail Sketch of the History of LifeChapter. 5. Early insights: a fascination with metabolic gradientsChapter. 6. How can metabolism lead to groups?Chapter. 7. Chemiosmosis and the origin of eukaryotesChapter. 8. Chemiosmosis and modern symbiosesChapter. 9. The evolution of multicellularityChapter. 10. Metabolism and multicellularity revisitedChapter. 11. Metabolic vestiges of conflict mediation in modern biologyChapter. 12. Conclusions