“The scientific analysis of behavior was defined first in opposition to the givens of naive consciousness. If I am in a dark room and a luminous spot appears on the wall and moves along it, I would say that it has “attracted” my attention, that I have turned my eyes “toward” it and that in all its movements it “pulls” my regard along with it. Grasped from the inside, my behavior appears as directed, as gifted with an intention and a meaning. Science seems to demand that we reject these characteristics as appearances under which a reality of another kind must be discovered. It will be said that seen light is “only in us.” It covers a vibratory movement, which movement is never given to consciousness. Let us call the qualitative appearance, “phenomenal light”; the vibratory movement, “real light.” Since the real light is never perceived, it could not present itself as a goal toward which my behavior is directed. It can only be conceptualized as a cause which acts on my organism. The phenomenal light was a force of attraction, the real light is a vis a tergo. This reversal immediately poses a series of questions.”

Maurice Merleau-Ponty