The meaning of essence in the topic of authenticity of existence is the truth that is expressed in response to what the object is. Also, one of the meanings of authenticity is something that is not the source of external objects. Allameh Tabatabai has referred to this credit nature as the limit of existence. This statement can be interpreted in two ways: a) nature is simply a concept that is abstracted from the limit of existence in the context of the functioning of the mind; b) The essence is the existential limit that the object has acquired in the context of the lack of existential perfections.  The second interpretation is liked by Allameh Tabatabai; Because he considers substantive concepts to be the direct reflection and conceptual realization and mental existence of truths that are realized outside, and on the other hand, he believes that if atsaf is in any container, both sides of atsaf are also realized in the same container. Based on this, the meaning of the limit of nature for existence is the second meaning.