There exists a tendency in nature to reduce complexity via modularization. This tendency grows when more modules become available. Finally this tendency enables nature to create intelligent and very sophisticated creatures. I encountered relations in several areas of physics and in human interactions. Physics is based on relations. Quantum logic is a set of axioms that restrict the relations that exist between quantum logical propositions. Via its isomorphism with Hilbert spaces quantum logic forms a fundament for quantum physics. However, quantum logic only describes static relations. Classical logic is a similar set of restrictions that define how we can communicate logically. Potential complexity of a set of objects is a measure that is defined by the number of potential relations that exist between the members of that set. Actual complexity of a set of objects is a measure that is defined by the number of relevant relations that exist between the members of the set. It takes time and other resources to determine whether a relation is relevant or not. Only an expert has the knowledge that a given relation is relevant. Thus it is advantageous to have as little potential relations as is possible, such that only relevant and preferably usable relations result. If there are n elements in the set, then there exist n*(n-1) potential relations. Actual complexity can be reduced by modularization, by applying standard module interfaces and standard inter-module communications, by increasing the diversity of modules and by increasing the availability of modules. Another important factor is the ease of modular system configuration. Nature secures its modules literally by brute force or when those binding forces are not available by enveloping the module in a skin such that only controlled access must be accepted by the module. Intelligent designers secure the integrity of their modules by power such as a patent mechanism or by proper encapsulation. The first measure secures the intelligence property that went into the design. The second measure guards against unwanted access that may hamper the integrity of the module. Still the module must have publicly accessible interfaces. Modularization can be done randomly, as is done in nature by the evolution process, or it can be done in an intelligent way as is done by human system designers. In the last case publication of the capabilities of modules and interfaces will reduce the complexity and increase the efficiency of system configuration and will increase the effectiveness of module and interface design. The system configuration process profits most from modularization, but reuse of modules and interfaces also saves resources and building time. The capability to create modules out of simpler modules gives the improvement an enormous boost. Providing tools for component and interface generation and providing system configuration tools will also reduce the complexity of system generation. Via modularization the complexity of system configuration can be reduced so strongly that it becomes possible to automate the configuration process. The complexity of a modular system can be many orders of magnitude less than the complexity of a monolith. Generation, management, improvement and support of modular systems normally cost a fraction of the time and the resources that the equivalent for a monolith or a layered system takes. Systems can be atoms, molecules, (in-) organic stuff, organs, living objects, products, modules, modular subsystems, organizations, governments, stars, galaxies, et cetera. A large availability, couple-ability and diversity of modules ease and stimulate the system configuration both in the random trial and error approach as well as in the case of intelligent system configuration. Too much diversity works negative. So there exists an optimum diversity both for modules and for interfaces. The same holds for availability. Too much availability exhausts precious resources, which are not used effectively and could be better used otherwise. Communication occurs via relations and via relation paths. It must be done via a well-defined protocol. Otherwise the communication makes no sense. Interfaces have a type definition. Not only the static aspects of the interface coupling play a role, also the dynamic properties may be important. There are provide interfaces and require interfaces. Sometimes they are combined in the same physical interface. Channels may connect require interfaces to provide interfaces. When they are well known, connected interfaces can be seen as a single relevant relation. In this way they replace a number of potential relations. Thus modularity enables and stimulates nature to create sophisticated creatures via a random process called evolution. The intelligent modular system creation process enables humans to create very sophisticated systems in much shorter time than nature took in order to create smart individuals. The laws of entropy are directed towards the increase of chaos. The tendency to reduce complexity via modularization works in the reverse direction. Both nature and intelligent system designers make use of the advantages of modularization. It enabled nature to create intelligent and very sophisticated creatures, such as human beings. It would be best to put the influence of modularization into a law of nature, but due to the complexity of the modularization process it is difficult to formulate such a law.