>7: Building Blocks (mechanism):    An internal model must of necessity be based on a limited number of samples of a perpetually novel environment, yet the model can only be useful if there is some kind of repetition of the situations modeled.   
>This paradox is resolved by the use of building blocks.  These component parts can be used and re-used in different situations.   For example, a face is decomposed to nose, eyes, and mouth, building blocks which are re-used even though the faces are different.
>We gain a significant advantage when we can reduce the building blocks at one level to interactions and combinations of building blocks at a lower level.  The laws at the higher level derive from the laws of the lower level building blocks.  
>Building blocks serve to impose regularity of a complex world.   They are used over and over again and refined in novel situations, and can be called up easily and combined and recombined when a new situation is encountered.
>The use of building blocks to generate internal models is a pervasive feature of complex adaptive systems.  When the model is tacit, the process of discovering and combining building blocks usually proceeds on an evolutionary time scale.  When the model is overt, the timescale may be orders of magnitude shorter.  The underlying process remains the same for all cas. 
>Complex adaptive systems are quite different from most systems that have been studied scientifically.  They exhibit coherence under change, via conditional action and anticipation.  At the same time, it would appear the cas have “lever points” where a small input produces large directed change.  
>We can uncover these lever points if we can uncover the general principals that govern cas dynamics.  This in turn would provide us with guidelines for effective approaches to cas-based problems such as immune diseases, inner city decay, etc.  For these complex problems we need theoretical guidelines.