  This paper initiates the dialectical approach to net theory. This approach
views nets as special, but very important and natural, dialectical systems. By
following this approach, a suitably generalized version of nets, called
dialectical nets, can be defined in terms of the "fundamental contradiction"
inherent in the structure of closed preorders. Dialectical nets are the least
conceptual upper bound subsuming the notions of Petri nets, Kan quantification
and transition systems. The nature of dialectical nets is that of logical
dynamics, and is succinctly defined and summarized in the statement that
"dialectical nets are transition systems relativized to closed preorders, and
hence are general predicate transformers".
