Alexander describes many examples of how nature continually produces this feeling of life through a “smooth unfolding” of change from what something is to what it becomes. He calls this a generative process. He goes on to describe how we as designers, can also create the same kind of life in the things we create by following similar generative processes. Being an architect, his focus is mostly on building processes, but there is no reason these processes cannot apply to (and he opens the door to) other domains; art, music, dance-or even the interactive application we create for kids.
He describes the generative process in book II of the series [Bk II, 216]. It can be expressed as a series of steps that can be applied iteratively to unfold more life through each cycle:
- At any given moment any evolving structure has “wholeness”. Actual and latent
- Identify what’s weakest in its coherence. Most deeply lacking in “deep feeling”
- Look for latent centers. Dimly, weakly present, but contributing to the absence of life
- Choose a latent center
- Apply one or more of the 15 structure- preserving transformations in its simplest form possible. Differentiate and intensify the center to strengthening the structure’s “wholeness”
- New centers will be born. Strength and coherence should be intensified in those centers, adjacent centers and embedded centers
- Test to make sure wholeness and “life” are intensified. Use the “Mirror of the Self” test
- If so repeat the process to further intensify wholeness. If not regress to the previous state
The process is not necessarily as rigid as it seems. Eventually it becomes rather intuitive, but even then the basic process remains; iteratively find centers that are weak and intensify them by intensifying one or more of the 15 properties.
One useful technique for identifying weak centers as candidates for strengthening is to compare centers of similar scope to each other using what Alexander describes as the Mirror of the Self test; comparing two centers side-by-side, to see which has more life?. The centers don’t need to be in the same creative wholeness as long as they can be examined relative to each other. The weaker centers, the ones with less life are candidates for transformation.