Where does the particular form or configuration of a pattern come from, and how is it propagated from pattern to pattern? Templets and the Explanation of Complex Patterns provides a natural language for analysing such questions. Using it, the organisational forces that underlie the fabrication of any pattern can be divided into two classes. First, there are the 'universal laws' of pattern assembly, the configurational rules and constraints inherent within the fabric of the pattern elements themselves. Second, there are the (...) 'templets' - external, situational constraints imposed on the pattern elements. From the perspective of templeting, simple patterns can be directly contrasted with complex patterns: the former are completely determined by their universal laws, whereas the latter also require extensive templets. Natural patterns range along the entire spectrum from simple to complex, and the most complex of these include both random patterns and many biological patterns. (shrink)

Most patterns of an organism develop reproducibly and predictably. Thus, most biological patterns are largely predetermined by the nature of the zygote and by the nature of the surrounding world. Some ontogenetic patterns can also be considered to be preformed. Eighteenth and nineteenth century definitions of 'preformation' suggested that all aspects of a precursor pattern--its elements and its configuration--are preserved during development. Today, the idea of preformed configurations has been lost. To revive this lost idea, we offer the following biologically (...) contemporary definition for preformed ontogenetic patterns: preformed patterns are those patterns with topologies that have been conserved during their ontogenies. This definition is presented in precise mathematical language, and its application is demonstrated in a system of developing, abstract patterns. (shrink)