The work improves spirit. This is its function, first and foremost. The Classics say: If you concentrate on spirit then you will be strong, but if you concentrate on qi then you will be weak. What does strong mean here? It does not mean big muscles, or great energy or masses of wealth and health, it means freedom, in particular the freedom that comes with vision, with being able to see, sense, suss the truth. Spirit cuts through veils, through lies, and exposes what's beneath. This is why, when your spirit is intense and burning, you don't feel happy – happiness does not come into it, happiness is for the herd – you feel eminently capable and you feel suspicious, as though you're starting to sense the forces, sinister or otherwise, underlying what you took to be reality. You start to sense depth. This depth is the beginnings of the Internal; and it's a never-ending process, as whatever your spirit exposes becomes external, and a new deeper layer of the Internal appears.