In this text, I connect the concept of existence worked out by Heidegger with the concepts of radical understanding. Under this concept I mean the idea that existence is the radical content of every understanding. The fact that according to Heidegger existence is understanding is then explained through their common structure: existence is possibility as well as understanding is directed prominently to possibility. But, as it is shown through wider references to ancient as well as to some contemporary discussions, possibility (...) introduces in the structure of existence a certain incommensurability: that is why existence can never be reduced to a positive, actual reality, but is always “something more” than actuality. (shrink)