In this paper a framework to study consciousness in animals is proposed which is based on a hierarchical organizational feedback model of the central nervous system, the separation of a given mental state into two components, i.e. an invariant part, and a variant part, which are separately related to the organization of the central nervous system, i.e. 'a neural network' and 'momentary active connections within the neural network determined by in- and output of this neural network' respectively, and phylogeny based (...) on the invariant part or the presence of a neural network. Consciousness is defined as a property of neural networks of self-organizing systems dedicated to dealing with rapidly changing environments affording flexibility of behavioural patterning. (shrink)