One can’t know self without knowing others. Even in Descartes’ ‘proof’ of existence of self, he had to acknowledge the existence of others as part of his presuppositions.
1. I think, therefore I doubt
2. I doubt everything, including my self-existence
3. When I doubt my self-existence, I need to first assume that I exist.
4. I think, therefore I exist (or I am).
When Descartes was doing step 3, he was treating his ‘self’ (the object) as DISTINCT from the ‘I’ (the subject), meaning that he was assuming that the ‘me’ can be treated as an OTHER. Therefore, the knowledge of self is inseparable from the knowledge of others.
How can human being have an awareness of self, as in the ‘I’ as a subject assessing the ‘me’ as an object? The only explanation is that human being is made in the image of the Triune God, who IS three Persons in His one being. No creature other than human being has self-awareness, which is fundamental in every endeavour to progress in human culture.