Instead of attacking the difficult problem of consciousness or self-consciousness directly, the theory is based on the more basic concept of reflection. A concept of reflection is suggested on four levels (recursion, reflective thinking, self-reflection, intersubjective reflection). We propose the glial-neuronal interaction as a neurobiological substrate for reflection processes. It is assumed that glia have a boundary-setting function (scaffolding, compartmentalization) in the spatio-temporal interaction with the neurons. This function could be a possible mechanism of 'dividing' the brain into different self-systems each with their own capacity of self-organization. Although the brain's different self-systems are normally integrated, they may disintegrate and show themselves in special states of the brain (e.g. multiple personality disorder). A tree of reflection consisting of a number of places (ontological loci) on which reflection processes of varying complexity take place, is suggested as the formal model. Finally, the problem of self-conscious qualitative experience (Qualia) is discussed in terms of the reflection model.