Merleau-Ponty: how is the subject's relation to space reorientated? 'becoming vertical' of perception. A tendency to see one way suggests about the relationship between bodies and space.
Normative axis: an effect of the repetition of bodily actions over time (production of the bodily horizon), a space for action: some objects are put into reach and others are not. It are those bodies that appear in line.
Vertical axis: an effect of being in line. It is normative and shaped by the repetition of bodily and social actions over time.