Is the individual identity of a person as perceived by that same person.

The self

Explanation:

In psychology, the sense of self is the way a person thinks of his/her own beliefs, characteristics, traits. In other words, the self is the individual beliefs  about himself/herself and who he/she is.

Therefore, it is the individual identity of a person as perceived by that same person.

the declaration states, “we hold these truths to be self-evident, that all men are created equal, that they are endowed by their creator with certain unalienable rights, that among these are life, liberty, and the pursuit of happiness….”