The first two parts of the series deal with the Financial and Health aspects of the Consistency philosophy. The last part of this series is effectively the vehicle in which the other aspects rely on: Personal Development.
Personal development entails all of the things that we do to improve our skills or abilities, which in turn enables us to be more productive, earn more money, and manage our time better. A high personal development skill gives us the necessary tools to increase our income or profits (and so improve the Financial aspect), as well as solidify the disciplines we need in our daily life (which improves the Health aspect).