10 OTHER NOTION QUARTETS
10.1 Life and knowledge quartets
Some aspects of reality can be viewed through the lens of Perception Spheres, but many others are defined by their own inherent quartets.
For instance, according to scientists, the language of the DNA code has only 4 ‘letters’; there are 4 human blood groups; humans can be described using four morphological and four temperamental types; natural cycles are based on 4 seasons and 4 lunar phases; four human races exist on our planet; our movement is guided by the four cardinal geographical directions wherever we go; all our mathematics is based on 4 basic arithmetic operations; the most basic 3D solid (the tetrahedron) has 4 faces and 4 vertices; we live in four-dimensional reality, where every physical event is defined by four key parameters (three space coordinates plus time). Furthermore, there are three primary colors of light (red, green, and blue) which combine to create the fourth fundamental color – white – as well as all other colors; physical stability is usually based on 4 supports – limbs, legs, wheels, walls…
Some of these and other quartets are presented in the following chapters.