Holons (Koestler) is a beautiful tool for understanding ideas that move in a few directions simultaneously (as opposed to transmission or transactional communication ). The concept of Holons states that a whole is part of another whole. Meaning can move up and down the meta-scale and in multiple directions at the same time. Meaning always points to another meaning. And the more meaning, the less language and openness there is.
Koestler wants to show two things with this parable [PDF, p.2]. First, that complex systems will evolve from simple systems much more rapidly if there are stable intermediate forms than if there are not, i.e. if they are hierarchically organised. Second, and more importantly, he wants to show that the resulting complex systems will always be hierarchic and that hierarchy is the natural and ubiquitous outcome of the development of structural form. After establishing the universal importance of hierarchy to the development of complex systems Koestler went on to propose that these hierarchies could be analysed in terms of the stable intermediate nodes or forms through which their structure is defined. It was to these intermediate forms that Koestler conferred the new label of "holon".