Abstract variations on a shape. Rules and theories of perceptual abstracting processes

Although perception or so called sensual cognition used to be treated as essentially irrational in the philosophical tradition, contemporary sciences of perception (as the phenomenology of the sensuous, the anthropology of the senses, the psychology of vision or psychology of aesthetic perception, Gestalttheorie, psychoaesthetics etc.) focus on some kind of logos implied in perception. Quasi-rational modalities of sensual (visual) perception – such as imagnation, memory, intuition and so on – work on visual sensory data reducing or/ and completing (filling in) them. The results of those processes can be called “abstractions”. The processes of abstracting are here defined by the idea of simplicity – on the one hand concerned as generalisation of the concrete and on the other as presentation of the specific qualities of the object. I would like to take into consideration different concepts of so called visual “notions” or “ideas”, to compare them and finally to put forward a risk hypothesis that a visual shape of abstract art (e.g. square) is a kind of a “notion” of visual perception