Humberto Maturana is one of the few authors that nowadays engage the construction of a wide, complete, explicatory system, comparable of those of Plato or Leibniz. His “autopoietic” approach includes also the origin of the observer, meant as a methodological prius who provide itself a view of the world. Here I try to follow the way Maturana sees the birth of “res cogitans” (entity which gains awareness of what it’s doing). I try to demonstrate that the basic activity of distinguishing can certainly lead to the distinction with which the observer is separated from anything observed. But I conclude that – at least for this interpreter – the origin of active consciousness remains obscure, that is, what works is the agent of distinguishing.