On the essence is the zubirian analyse of the reality in general and the human reality in particular. The reality does not have a substantial structure but substantive, and the essence is not therefore essence of the substance but the substantive reality. In addition, in the transcendental order, the essence is either closed or opened. In the world, the human reality is the “opened essence,” the intellective essence that is usually called “person.” The person notion is thus the aim of detailed metaphysical analysis of the reality. However, the person notion as “open essence” creates the same problems. In 1962, Zubiri thought that intelligence was an essential note that performed a special role in the structure of the human reality. Nevertheless, since 1973 Zubiri analized the intelligence like systematic or substantive note. Then “open essence” becomes “open reality.” In this communication, we tried to discuss this problem with the purpose of clarifying the position of Zubiri and perhaps its evolution.