Feng shui divides broadly into two branches according to its object. One is the yang abode, which examines the ground of houses and villages where the living dwell; the other is the yin abode, which examines the site of the graves that honor the dead. The yang of the yang abode was held to denote bright, living energy, and the yin of the yin abode quiet, reposing energy, so that although they follow the same principles of feng shui, their use and emphasis differed considerably. Traditional society treated both as important, prudently examining together the place to live and the place to be buried.
The yang abode and the yin abode are said to differ first in the way directions are applied. Because the yang abode is a space people enter and live in daily, it broadly examines directions bound up with human movement and everyday life, such as the orientation of the main gate, the inner room, and the kitchen. The direction the sunlight enters, the paths by which wind passes, and the place where water is used all became objects of consideration. The yin abode, by contrast, is a space that remains in one spot for long, so the exact point of the node where mountain ridges flow in and energy was thought to gather, and its orientation, were weighed all the more finely.
In the scale of the energy ground, too, the two were seen to differ in grain. Because the yang abode is a place where many gather to live and houses, yards, and paths blend together, a relatively broad and open site was held suitable; it needed a wide embrace able to hold a whole village. The yin abode, by comparison, being a place that honors a single person, prized a tidy, compact small site where the mountain forms were thought to converge and energy to concentrate. Finding one finely harbored point, rather than a broadly spread ground, was held to be the heart of the yin abode.
In the influence each was thought to bring, the difference in traditional notions also appears. The yang abode was held to bear directly on the living environment and health of those who dwell within, and on household fortune, the circumstances of the family. To live in a good yang abode was thought to make body and mind at ease and the livelihood stable. The yin abode, meanwhile, was tied to the notion of prospering, that blessing reaches descendants through the ancestor honored there. The thought that placing an ancestor in a good site transmits its energy to the descendants was deeply meshed with the values of a traditional society that prized filial duty and the lineage.
Coming to the present day, a clear change has appeared in the use of the two. As city dwellers grew more numerous and the forms of housing changed, what is in fact widely put to use is chiefly the yang abode, that is, the living feng shui that treats spaces of daily life. This has carried over into an interest in tending the everyday environment to be comfortable and balanced, such as the layout of homes and offices, lighting and ventilation, and the placement of furniture. This is interpreted as a current in which the original aim of the yang abode, to refine the space where people stay in harmony with nature, meets a modern sense of living.
The yin abode, by contrast, has shifted in weight along with changes in burial culture, yet it is still treated meaningfully within the cultural-historical context of understanding our traditional burial culture and the devotion shown toward ancestors. The tradition of the yang abode and the yin abode, which examined with care together the place to live and the place to be buried, is said to hold whole the worldview of the ancients, who beheld life and death within the great flow of nature and sought harmony within it.
In the city apartments where many people live today, in particular, the yang-abode feng shui is read anew along a fresh grain. Since it is hard to set one's back directly to a mountain and face water in such surroundings, the traditional principle of mountain-behind-water-ahead is often carried over and read in urban conditions such as the orientation of the building, the surrounding roads, and the placement of tall structures. One examines, for instance, whether light and air enter the home well so that it does not feel stifling, whether the path from the entrance to the living room flows naturally, and whether the bed is set in a position that feels stable. Seen this way, urban yang-abode feng shui can be called a current that, rather than transplanting the old principle as it stands, reinterprets the original aim of tending the space where people stay to be comfortable and at ease, fitting it to the housing forms of today.