The model and its application, simulation, have got an ever increasing weight as instrument in many disciplines since computers became available. At the same time new scientific theoretical approaches have been developed in order to classify and systematize this method. In this paper an approach is discussed, which describes the modelling method on the basis of the theory of science. The hypothetical statements as formulated in the paper perhaps serve as stimulus for further work in this area and could contribute to the more common understanding of the phenomena of modelling in the context of intelligent and rational behaviour. A model theory has been presented by Stachowiak /1973/ as a fundamental contribution to the theory of science, which is seen as the basis and starting-point for the contribution in this paper. Most important attributes of models are:

• purpose

• model-original-relation

• contraction.

The intellectual feedback cycle of models is the principal element of the paper which can serve as an extension to the theory of modelling. The distinction between perception models and anticipation models is introduced as well as the hierarchical or fractal approach to describe systems of model applications in the context of intellectual behaviour. Examples of real life systems are discussed and presented.