In contemporary philosophy of mind and psychiatry, a phenomenon that attracts a lot of attention is a symptom of schizophrenia called thought insertion. People living with thought insertion claim that some of the thoughts they experience are not produced by them and are authored by someone else. To explain this phenomenon, philosophers and psychologists commonly distinguish between the sense of being the subject of one’s mental activity and the agent of that activity, arguing that thought insertion involves a breakdown in the sense of agency for some thoughts. Given this explanation, recent work has concluded that we normally have a substantial experience of ourselves as the thinker of our thoughts. In this thesis, I argue against this conc...