In his seminal work I and Thou, Martin Buber explored the relationship between subject and object. Here are a few lines from the beginning of his text. I interspersed comments [within brackets] to indicate relationships with the Three Minds framework.
Martin Buber:
"To man the world is twofold [relational and separate], in accordance with his twofold attitude. The attitude of man is twofold, in accordance with the twofold nature of the primary words which he speaks. The one primary word is the combination i - thou [relational]. The other primary word is a combination i - it [separate]; wherein, without a change in the primary word, one of the words He and She can replace It. Hence the I [identity] of man is also twofold. For the I of the primary word i - thou [nearer to M2] is a different I from that of the primary word i - it [M1-O, but M1 is not recognizing its role and therefore interprets M1-O as simply O, an apparently independent object].
Primary words do not signify things, but they intimate relations [subject-object relationships, M1-O relationships, M2-M1 relationships]. Primary words do not describe something that might exist independently of them, but being spoken they bring about existence [word, thought, and identity reflect each other]... The primary word i - thou can only be spoken with the whole being [nearer to M2, or M2-(M1-O)]. The primary word i - it [M1-O, experienced as O] can never be spoken with the whole being... When a primary word is spoken the speaker enters the word and takes his stand in it."
Buber's I and Thou is available free online.