A psychological identity relates to self-image (one's mental model of oneself), self-esteem, and individuality. Consequently, Weinreich gives the definition "A person's identity is defined as the totality of one's self-construal, in which how one construes oneself in the present expresses the continuity between how one construes oneself as one was in the past and how one construes oneself as one aspires to be in the future"; this allows for definitions of aspects of identity, such as: "One's ethnic identity is defined as that part of the totality of one's self-construal made up of those dimensions that express the continuity between one's construal of past ancestry and one's future aspirations in relation to ethnicity" (Weinreich, 1986a).