Tertiary entities and ternary mechanisms
What are tertiary entities?
Once we have accepted the idea that the three-domain structure is a stratified menu of ontological commitment, then it follows that the next stage in the argument is to decide what tertiary entities we ought to consider as existing in order to help us forward with the construction of a complete cybernetic science. Both the theory and the practice of cybernetics require an ontology which includes categories for goals, policies, conventions, and other things involved in mechanisms of purposive activity. Are these what we are going to mean by 'tertiary entities'? How are we to recognise a tertiary entity when we see one?
The very brief answer to that question must be that tertiary entities will consist of pure imparity. The simplest example might be a vote, and a completed ballot paper would therefore be a ternary mechanism (that is, one involving components in all three domains). Spranger's dimensional scheme for values provides a framework for the kind of dimensional analysis that can be made of the tertiary domain.
Spranger's dimensions of value
The practical pursuit of values needs ternary mechanisms
We would expect ternary mechanisms to be involved in the practical pursuit of those values. None would be likely to be purely in only one dimension, but examples might be chosen to illustrate how each can have a leading dimension. Examples for this purpose might include: a company's memorandum of association, a mission statement, a policy document, an aesthetic (such as 'modernism'), a fashion, a charity, an act of parliament, a party manifesto, a religious creed—and an example in which the theoretical dimension is leading might be this scientific account!
I suggest that, in the real world, practical work involving purposive behaviour ought to consist of seeking out, or constructing from scratch, such ternary mechanisms as these, analysing them, and perhaps modifying them.
Other kinds of mechanism often don't succeed
This prescription can be sharply contrasted with what seems to happen at present. An important class of examples is the behaviour of managers, politicians, and legislators. It is very common for them to execute some policy which in the event has the opposite effect to what they apparently intended. This sort of situation seems to be characterised by a sort of wishful thinking—a belief that having a formulated purpose somehow directly acts to bring about the desired result, quite regardless of what kind of mechanism is being constructed.
It may be that those politicians and legislators are still working with Aristotelian teleological concepts and unary mechanisms—and continue to reject any mechanistic conception of purposive activity, however sophisticated. They may have heard of management cybernetics, but have only the haziest idea of how a binary mechanism works and, naturally, none whatever about a ternary mechanism.