Can all the components in a complex system be understood?
We can completely understand all the components of a complex system, and even how each interacts with any one other component. What we cannot do is calculate accurately all the three-body, four-body, etc. interactions. If you consider that solving even a three body problem analytically is not generally doable (except for some special cases, and/or with simplifying assumptions) it becomes obvious that we cannot solve the general equations governing the development of truly complex systems. What we can do is look at average behaviors of large ensembles of particles, and get very accurate predictions. However, the length of development time over which the accuracy remains good is very short for highly chaotic systems (e.g. weather patterns).
