The purpose of this e-book is to explore the potential of the metaphor of capital, and to chart the recent development of the multiple capitals concept in the International Framework and consider how it might develop and be used. We argue that opening up what is capital and integrated thinking on how we conceive of multiple capitals and their relationship is critical to debate on sustainable development and practice. The concept, or metaphor, of multiple capitals is relatively new and is certainly new in its application to corporate reporting, organisational accounting and business thinking, and hence there are numerous avenues for further research.