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Not-self (Pali: anatta; Sanskrit: anatman) is the third mark of existence. Upon careful examination, one finds that no phenomenon is really "I" or "mine"; these concepts are in fact constructed by the mind. In the Nikayas anatta is not meant as a metaphysical assertion, but as an approach for gaining release from suffering. In fact, the Buddha rejected both of the metaphysical assertions "I have a Self" and "I have no Self" as ontological views that bind one to suffering.[note 9] When asked if the self was identical with the body, the Buddha refused to answer. By analyzing the constantly changing physical and mental constituents (skandhas) of a person or object, the practitioner comes to the conclusion that neither the respective parts nor the person as a whole comprise a self.

What is the third mark of existence in Buddhism?
Not-self (Pali: anatta; Sanskrit: anatman)