Many philosophers and consciousness researchers today support the idea that consciousness is not singular.* Even though it makes things simpler to speak as if I" means the same thing all the time, even our casual speech reflects our appreciation that we are a multitude: "Well, one part of me likes the idea, but another part is really against it; but then again, another part wants . . ."
Early in the last century, Georg Gurdjieff, an astute teacher and explorer of the human psyche, pointed out that we are run by a vast number of "I's" all vying with each other for attention and dominance. He identified three centers of consciousness, each with its own "I's": the intellectual (thinking or mental), the emotional (feeling), and the moving (action-based) center. Gurdjieff explained that one or more of our thinking "I's" can often be at odds (if not at war) with our feeling-based "I's," and either or both can be in conflict with our action-based "I's"; for example, the "I" that set the alarm clock last night, firmly intending to get up for that early-morning jog in the park, is not the same "I" that heard the ringing in the morning, turned the clock off, and rolled over for an extra hour of sleep. In other words, not only is there potential confusion in the intellect about who's running the show, but that confusion can spill over into our emotional responses and actions as well.
Ordinarily, we limit the idea of "thinking" to something that happens in the cortex of our brain. Yet, the more we learn about the nature of the body, the more we find that our cells have a type of consciousness, a type of memory, a type of intellect that makes connections and directs activity. Author Carolyn Myss (The Creation of Health and Anatomy of the Spirit) sees evidence in people's lives for how our memories are literally stored in the cells of our tissues throughout the body.
* Tart, C., Waking Up: Overcoming the Obstacles to Human Potential