Capitalism is synonymous with money or credit. That is wrong. Capitalism has to do with an abundance of valuable resource under exclusive control. Money or credit is not a valuable resource—merely the capacity to complete transactions. Therefore, it is possible to have a capitalistic economy without any money even though the presence of money or credit will greatly facilitate transactions.
This means that capitalism theory applies in many more avenues than within and between nation states. An individual can take advantage of capitalism theory if it is the case that he/she has an abundance of some resource such as reputation or skill even if he/she may be dirt poor. It also means that there are other artefacts which can play the role of money or credit. Even the word credibility fits well with my definition.