Some time I ago I hazarded 3Cs of complexity. At the time Daivd Cronshaw suggested I add context which was a good idea, and I also want to add coalescence to make it up to five. I'm going to run those out at a keynote this lunch time, so in summary here they are:

• Constraint is key to understanding complexity, it governs the transition between the three ontologies. Increase constraint and you create an ordered system; do that inappropriately and you create the conditions for catastrophic failure; remove constraint and the system is chaotic. Lightly constrain the system, while allowing it to be modified by the actors within it and you enable evolution and the emergence of meaning. Managing constrains is one of the things you can train managers to do, and measure their capability and effectiveness.
• Coherence is the measure and concept by which you judge the validity of an action in a complex domain. A lightly constrained system modifies as agents interact with it, but it does constrain. The constant change means that is it difficult to provide absolute proof of an idea or approach (by the time you did the situation would have changed), but it is possible to create tests (including mathematical tests) of the degree of coherence that an idea has.
  
• Connectivity is key to a complex system, where agent proximity has a massive impact on agent action. Of course the nature of connections is also key (just connecting things is not enough. If I increase connectivity I can increase variety and thence novelty by the right selection of links. But I can also increase connectivity of like with like if I want to exploit existing knowledge. I may generate a higher or lower degree of coherence, or at least test my ability to do so.
  
• Context is vital. I remember a great advert for the Guardian newspaper. In the first scene you see a skinhead running towards a women; the perspective shifts and you see him about to grab a middle aged man with a briefcase; the perspective shifts and you see him drag the man into the doorway before a skip of building material would have fallen on his head and killed him. We need to acknowledge perspective but it doesn't follow that we can never be objective.
• Coalescence is an alternative to categories which are all to common in management speak. We like to put things into little boxes so we have them properly organised. Its better to think about things as the centre of a coalescence with fussy boundaries Interestingly we are starting to understand that this is the nature of our own mind. Its a distributed function of our brain, hormones, nervous and tactile systems and in all probability toe environment. Categories lead to stereotyping, coalescence to meaning

Now I could add a sixth, namely Cynefin the model that sorts it all out! But that would make it six, and I need one more to make it seven. You can't have an even number in a list!