What are we to make of people who claim to "hear" voices in their heads or who swear that their thoughts are manipulated by outside forces? To some extent, we all have an idea of what that’s like–perhaps reaching for that cookie before sitting down to eat dredges up a mother’s warning about ruined dinners. Personally, some of what I think are my best thoughts seem to come out of nowhere. But what about the more extreme cases of this phenomenon involving schizophrenic subjects who sincerely believe that some of the thoughts in their own heads are literally not their own?

G. Lynn Stephens and George Graham propose in their humble and witty book to take such schizophrenics at their word. In respecting the phenomenology of what they call "alienated self-consciousness"–namely what it’s like for the subjects to "hear voices" or experience thoughts that seem imposed upon them in one way or another–Stephens and Graham believe that we can deepen our understanding of how we think about ourselves. Theirs is a good strategy: Using pathological cases as wedges into conundrums in psychology and the philosophy of mind has lead to valuable insights about the brain and cognition.

Taking these schizophrenics at their word in this case, however, seems far from easy. It’s certainly not immediately clear that what they claim transpires in their mental lives even makes sense. By far the most perplexing cases of alienated self-consciousness involve those who profess to suffer from thought insertion, or episodes in which subjects recognize a thought as occurring within their own stream of consciousness but view it, quite literally, as someone else’s. The challenge in understanding both "voices" and inserted thoughts amounts to making sense of what it means to think that you have someone else’s thoughts scattered amongst your own.

Stephens and Graham work their way into this problem by looking to psychologists’ attempts to come to grips with the phenomenon of auditory hallucinations or "voices". Ralph Hoffman’s work serves as their main point of departure. He endorses a version of the auditory-hallucination model (AHM), under which certain experiences seem alien because schizophrenics mistake bits of their own "inner speech" or verbal imagery for the external speech of someone else. The root of the mistake in speech attribution, Hoffman offers, results from those thoughts seeming completely unintended to their thinker. (For Hoffman, as for Stephens and Graham, the phenomenology of voices–what the voices themselves actually "sound" like to their subjects–results from certain thoughts being considered alien, not the reverse.) Stephens and Graham argue that Hoffman’s proposal suffers from several difficulties, however, including falling into circularity when trying to account for what it means for instances of verbal imagery to be unintended. Furthermore, the AHM model in general can’t explain cases where subjects report experiences of alienated self-consciousness such as thought insertion that lack auditory or voice-like characteristics. Preferably, Stephens and Graham contend, we want a theory that can explain alienation in general.

Nevertheless, Stephens and Graham find a valuable insight in Hoffman’s work: Self-consciousness involves a sense of mental agency, an impression that I think or I say such and such. Explaining alienation, then, requires respecting a distinction between what they call the "subjectivity" of a thought and its "agency". That is, we must be able to make a distinction between identifying the thought as occurring within a person’s ego boundary and the degree to which it is under her control, and self-consciousness "breaks" in the schizophrenic’s case when these two components of self-consciousness seem to come apart. Though a person may have the thought that she should "Kill God" (to borrow a vivid example Stephens and Graham themselves take from Christopher Frith), she doesn’t think it.

Does it make sense for someone to have a thought yet not think it? Stephens and Graham think so. Looking to an example due to Harry Frankfurt, we can understand the difference between my intentionally raising my arm and someone else grabbing my arm and lifting it. From the inside as it were, the two seem quite different, for though I know that my arm is going up in both cases, in the second I experience it as going up whether I want it to or not. Similarly, alien thoughts are those that I experience as within me but seem beyond my control. A subject concludes that a particular thought is beyond her control, Stephens and Graham explain, due to her conviction that she can’t accommodate that thought within her current conception or overall "theory" of what she believes and desires. As the authors put it, "your awareness that you are doing something requires having a sense of what you are doing and why you are doing it" (p. 165), whether it be thinking or more traditional forms of observable behavior. If the subject doesn’t seem to be in control of a thought, someone else must be.

Though Stephens and Graham give us a way of making sense of how schizophrenics experience their mental lives, the lesson applies to us all. Self-consciousness in general involves not only a sense that one’s thoughts belong to oneself but also the conviction that one thinks them, where the sense of agency in regard to thinking a thought depends upon one’s picture of one’s own beliefs and desires. Though we might think that this picture could have further philosophical implications, Stephens and Graham caution against wide ranging metaphysical speculation. The distinction is ultimately a conceptual one, and though schizophrenics take certain thoughts of theirs in some instances to belong to another, we consider all their thoughts to be in fact their own.

Questions do remain, however. The analogy between raised arms and inserted thoughts only goes so far. For example, it doesn’t seem able to capture the distinction subjects themselves make between those thoughts they experience as their own but are influenced by another and those literally taken to be in them but belonging to someone else. In addition, if the subjectivity and agency of thoughts can come apart as Stephens and Graham believe, it should likewise be comprehensible for a person to experience her thought as falling outside her ego boundary yet within her control. For these reasons, I’m less confident that we can actually make sense of what schizophrenics describe in episodes of thought insertion taken literally, however sincere those descriptions. And though I do agree with the central distinction Stephens and Graham make, I would have liked more discussion regarding the relation between the two. Presumably a person can experience only so many thoughts as alien before her sense of subjectivity–who she thinks she actually is–becomes problematic for her. Also, noticeably absent from the conversation are philosophers such as Gareth Evans, John Perry, and José Luis Bermúdez who acknowledge a similar and no doubt related distinction between a subject’s knowing who a thought is about and her acting on that thought. These latter two conditions are closely related, for the behavior resulting from self-conscious thoughts considered in this way derives from one’s recognizing who the thought is about without having to identify its subject. Someone taken by what Stephens and Graham propose might think more needs to be said here, perhaps concerning the degree to which one can recognize another as the author of one’s thought yet still have that thought directly impact one’s behavior.

Despite these few imperfections, Stephens and Graham have done a commendable job of integrating a respectable amount of complex philosophical and psychological literature in a way that illuminates and extends both fields. Moreover, readers of all backgrounds will find this book approachable–no small feat given the subject. The various cases of mental maladies certainly make for interesting reading, and Stephens and Graham work through this puzzling material in an engaging and readable way. Perhaps the best example of the power of voices and thought insertion is the book itself. Together, Stephens and Graham deftly unite a host of voices from psychology and philosophy (as well as their own) to produce an insightful contribution to the difficult discussion of self-consciousness. We would do well to listen.

Roblin Meeks is finishing a Ph.D. in philosophy at The Graduate School and University Center of The City University of New York, and is currently teaching expository writing at Harvard University.

Buy the book from Barnes & Noble.com: When Self-Consciousness Breaks: Alien Voices and Inserted Thoughts