The "I", the "self", or the "agent" is the conscious part of the organism which also experiences the acts of will in the sensory-perceptions.
Perceptual Control Theory (PCT)
The main idea in PCT is that the biological organism has sensory feedback systems that enable the effort to control perceptions and to keep perceptions within some acceptable, tolerable, or desired limits. Then the "I" is the conscious part of the biological organism which experiences those efforts as desires, actions, and the self as a cause of perceptions.
In my opinion the core theory of PCT is valid based on introspection but the effort to describe models of the self or of the not-self all go off the rails eventually. The distinction between self and not-self arises in the field of awareness before any model of the self or not-self can take root and have concrete meaning. The belief in biological causes is one in which my self believes that the not-self is more fundamental and preexisting thing but the self is witness to all the thoughts of not-self.
Suffering
Suffering is an experience that the biological organism tries to avoid. One might introspect and discover that the "I" is that within the organism which consciously suffers the experiences we call pain and/or disability. This is not the whole experience of the "I" or self-awareness but it seems to be the most acute and intense motivation of the "I" or self - to avoid intense pain or disability.
The Buddha taught that all phenomena, including thoughts, emotions, and experiences, are marked by three characteristics, or “three marks of existence”: impermanence (anicca), suffering or dissatisfaction (dukkha), and not-self (anatta).
The Buddha claims to teach that life evokes suffering and there is a way to put an end to suffering. The doctrine of not-self is part of this remedy.
The problem I have is that not-self is only meaningful as negation of self. Transcending drama would mean no distinction arises between self and not-self. I cannot transcend drama except when meditating or enrapture in nature without concepts arising of self, others, or animals. When I am in pain the sense of self is most acute. During some activities that generate euphoria there are no active distinctions arising between self and not-self. In the past the sense of self would often drop out during peak academic (test taking) or athletic performances, with a sense of euphoria, but my personal intentions were still to dominate some external adversary in the context of drama. The euphoria of just being part of the vast universe with a sense of beauty is qualitatively better in my memories than the drama of competing for potential social rewards.
Sigmund Freud
Sigmund Freud is the founder of an ethical philosophy called psychoanalysis. In my interpretation of human behavior, Freud confused his ethical philosophy with the practice of medicine, and the so-called experts in mental health or talk therapy went off the rails in their efforts to imitate Sigmund Freud as self-appointed healers. These people remind me of the community of mothers, who find fault with the behavior of men and children, and then try to remedy their behavior, forming a super-group with the claim to authority on the meaning of behavior. I think the so-called Patriarchy can be highly sadistic and moralistic but the children internalize patterns of moral judgment mostly during early life with the biological or social mothers (primary caregivers).
Freud maps the "I" to the conscious and unconscious parts of the biological organism that make efforts to govern action in the sensory context. This "I" was written in German (I think) and later translated into the term "ego" in the English language. The ego is the name for a set of biological functions inside the organism, these functions are the efforts to control perceptions, and the ego idea predates the concepts developed as PCT.
Free Will
Sigmund Freud says the ego is subject to two external sources of cause. These are the biological source of inner drives (the id) and the causes that map to the external world (reality). Psychoanalysis is an effort to understand what happens to the biological ego when the body, driven by biological needs, interacts with the external world of human affairs and natural forces. The main idea is that there are three independent sources of cause in the sensory context. The ego must become a more effective source of cause against the potentially superior impulses coming from the id and the often adverse social and natural forces that map to external reality.
Hugh Gibbons, my professor of Torts and Legal Philosophy (1990-91), describes the will as the expression: I am the cause of my desired perceptions. So, if one is making a Marini to suit one's own taste, then the will is effective because the self is the sole cause of desired perceptions. This concept of the will as a source of cause of desired perceptions is derived very broadly from PCT.
The law, in essence, reduces sources of cause to Acts of God, acts of man, and acts of nature. The law recognizes distinctions between the nearby proximate cause and the remote ultimate cause; between a source of moral cause (man) and sources of supernatural or natural cause (God, Nature); and between a sole cause and a joint cause. Free will falls apart if the ultimate cause of efforts to govern action in the sensory context or perceptual control efforts map to something not in the control of the human will.
Free will is the idea that my efforts to govern action in the sensory context (ego efforts) are the sole effective cause of my perceptions. This is often true in the context of experience. However, it is also true that the external sources of cause are joint causes of perceptions that are not under the sole exclusive control of the human will. I would say that identity, or the sense of self as a source of cause independent from sources of cause that are not-self, is more fundamental than the concept of free will. The experience of the human will emerges in the context of biological self and of forming a unique personal identity.