When looking at the yin/yang pairings of the officials within each element, and trying to work out how each expresses this element in its own characteristic way, it is good to visualize the yin official as hidden deep within us, with its yang companion forming a pathway along which the yin official's energy can be drawn up from within the body to the outside. It is useful here to remember that one of the main reasons why we only tap for Aggressive Energy on the yin AEPs (back shu points) is because the yang officials have this escape route to the outside which allows any Aggressive Energy to be released. By contrast, AE remains trapped within the yin officials, and needs to be coaxed to the surface through the needles we place on their yin AEPS, since they have no escape route of their own to enable them to get rid of any AE which has accumulated.
It is always good to visualize this difference when thinking of the different qualities which the yin and yang officials give to the element. The yang officials are much more mobile and active, the yin more static and reflective, a distinction which helps us define their differences a little more closely. Nowhere is this contrast more obvious than in the relationship of the yin and yang officials within the Wood element. There is a very obvious difference between how we plan things, which is the Liver's task, and how we then go on to decide which of these plans we will carry out, which is the Gall Bladder's task. I have always visualized the Liver as taking on the role of a general sitting his tent on the field of action, with his maps spread out in front of him as he makes his plans, whilst the Gall Bladder is the officer in charge of the army deployed on the battlefield, tasked with carrying out the general's instructions.
There is a very clear distinction here between the Liver in his tent and the Gall Bladder actively fulfilling the plans of attack which the Liver has handed over to him. This is a clear illustration of the yin nature of the Liver compared with the very yang nature of the Gall Bladder. When we look at our Wood patients, therefore, we may gradually learn to differentiate between these two different qualities, which will eventually help us diagnose our patients as having either the Liver or the Gall Bladder as their particular guardian official.