Below is an essay by Professor Alesandra Tanesini from the Cardiff School of English, Communication and Philosophy (ENCAP) at Cardiff University and relates to our sciSCREENing of Inception last August. 'Compare the question: ‘Someone left the oven on. I wonder whether it was me’ with the question: ‘Someone in this room is thinking about making tea. I wonder whether it is me’ (or the question ‘Someone in this room is in pain. I wonder whether it is me’). The first question makes perfectly good sense, but the second does not. It is often said that the reason why the second question is absurd is that although one might be mistaken about what one is thinking, one cannot be mistaken whether it is oneself that does the thinking. If so, there is something special about one’s knowledge of one’s own mind. If I know of a current mental state by introspection, I cannot misidentify the owner of that state. The mental state must be mine; the owner must be me. In philosophical circles this privileged feature of knowledge by introspection of current mental states is known as Immunity to Error through misidentification. The idea that I am the owner of all those thoughts which I can currently introspect is seemingly undermined by the phenomenon of thought insertion. This is a symptom of psychosis, most commonly schizophrenia. Patients manifesting the symptom, report that there are thoughts in their head which are in some sense ‘not theirs’. Here is one such report: ‘I look out of the window and I think the garden looks nice and the grass looks cool, but the thoughts of Eamonn Andrews come into my mind. There are no other thoughts there, only his. . .He treats my mind like a screen and flashes his thoughts onto it like you flash a picture’ (Mellor, 1970, p. 17). These patients claim to be finding, by introspection, thoughts in their head which they claim not to be their own. What are we to make of this? How can we make sense of what is reported by these patients? What are they trying to convey when they say that some thoughts that they can introspect are not actually theirs? Some philosophers and psychiatrists have answered these questions by way of a distinction between ownership and authorship of mental states. These patients would retain ownership of the so- called ‘inserted thoughts’, but their ownership is alienated because they do not see themselves as the authors of the thoughts in question. Ownership in this context becomes a thin notion. An occurring thought is one’s own whenever it is experienced as being in one’s own head. Authorship, on the other hand, requires that one thinks of oneself as the cause of the thought or as in control of the thought. Subjects who report inserted thoughts, own their thoughts. What they are trying to convey is not the presence in their head of other people’s thoughts. Rather, what they are saying is that some of their thoughts have been implanted there by other people who are the authors of these thought. Thus, what the patients are reporting is a sense of passivity with regard to their own thoughts. Is this a good explanation of what is going on? First, it does not do justice to what the patients say. They report these thoughts as being not their own. For them, it would seem, it makes sense to ask of a thought they know, by introspection: is this mine? Or is it somebody else’s? Second, it cannot explain the difference between ‘inserted thoughts’ and the experience by normal subjects of thoughts that just pop into one’s head out of the blue, or thoughts one cannot stop thinking. In neither case, does the person think of herself as in control or as the author of the thought. Yet, normal subjects do not think of these thoughts as alien, as not their own. Third, the account relies on an inadequate definition of ownership of mental states. It assumes that there is a space, the space of what is illuminated by introspection, such that anything that can be found there is mine. This account strangely detaches the person from her own mental states. Contrary to this view, for a thought to be one’s own it is not enough that it can be found by introspection within one’s mind, so to speak, the thought also needs to belong to oneself in the sense of being acknowledged as one’s own. We can, thus, draw a somewhat general lesson from the ‘thought insertion’ cases. What makes a thought mine is not the fact that I can introspect it, or the fact that it is found in my mind. Further, I do not need to think of myself as the author of the thought. What makes a thought mine is that I acknowledge it as my own; I ascribe it to myself, and take responsibility for it. In other words, a thought is mine only when it is bound up with my own sense of agency, of what I am responsible for. So what are we to say of the case of ‘thought’ insertion? I think that when patients report that they have in their head thoughts which are not theirs, their claims should be taken literally at least in part. (I say in part, because their attributions of the thoughts to other people are delusional.) We could say that due to a disruption to their sense of self or agency, thoughts happen in their head which are not owned by them or anybody else. However, given the repugnancy of the idea of un-owned thoughts, the best answer is that things happen in these patients’ consciousness which they assume must be episodes of thinking, when in fact they are not. To conclude, we might be wrong about what we are thinking, and although it is not possible to be mistaken about whether it is ‘I’ that does the thinking, sometimes one might be mistaken as to whether what goes on in one’s experience is actually thinking.' References Bortolotti, L. and Broome, M. 2009: A role for ownership and authorship in the analysis of thought insertion. Phenomenology and the Cognitive Sciences, 8, 205–24. Campbell, J. 2002: The ownership of thoughts. Philosophy, Psychiatry and Psychology, 9, 35–9. Gallagher, S. 2000: Philosophical Conceptions of the Self: implications for the cognitive sciences. Trends in Cognitive Science 4, 14-21.Mellor, C. S. 1970: ‘First Rank Symptoms of Schizophrenia’ The British Journal of Psychiatry117, 15-23. Mullins, S. and Spence, S. A 2003: Re-examining thought insertion: Semi-structured literature review and conceptual analysis, The British Journal of Psychiatry182, 293-298.