Juan, Interesting thread! I have a few questions regarding your post. You wrote: "A photon can contact a sensory surface in the eye but the computer does not contact the sensory surface of the eye. The nervous system can not make the mapping between the computer and parts of itself so that parts of itself can be symbols for the computer." When you refer to "parts of itself" regarding the nervous system, are you referring to representations or nerve cells? Also, your example refers to the visual system. How would you situate the kinesthetic piece of representation that is created when I touch the computer? Aren't representations symbols and vice-versa? You wrote: "I don't speak in terms of filters but if i were to, i would say that thinking of systems as if they were operating with representation of what is external to them is one of the most pervasive F2 filters that we have." Are you referring here to metaphor? Something as "The human body is like the hardware of a computer and the mind is like the software."? You wrote: "In fact what I think it does, is to hide the possibility of explaining the operation of natural systems in terms of what they do (or what we observe they are doing)." When you use the term "explaining", do you mean "describing the operation" or "describing how the operation works" or "describing what makes the operation work" or something else? You wrote: "We are trying to explain the operation of systems in terms of their relations to other systems (or better in terms of the relations that we as actors or observers see with other systems), so we are not explaining them. We are culturally trapped in this." Could you provide a few examples of where you witness or hear this happening? I'd love to find out more! Rock on! Martin