Time and object are elements of the meta-structure of our knowledge, yet in conflict with the general change in the world. Time and object are shown to be products of our decomposition of change. Accordingly, there are no objects (and subjects) in the world: the object is the concept and its meaning is its relative position in the structure of knowledge. Thus, the referent is the concept and perception is the result of interpreting raw sensation within this conceptual structure. The material signifier of all our concepts is the sensation thus being the clay with which we shape our representations of the world. However, it is impossible to represent the clay itself using clay as material signifier. Therefore, the explanatory gap is nothing more than the un-closeable gap between signifier and signified. The gap can only be closed when filled with sensation (thus becoming part of the physical world). http://webs.uvigo.es/jmmatias/knowledge/knowledge.htm