  Another way in which levels talk has featured in recent philosophy of psychiatry is as a constraint on permissible kinds of explanation. Chris Frith (1992, 26) for example, imagines what we would say if we found a strong correlation between a spike in dopamine levels and delusions of thought insertion (in which, for example, one has the experience of another person’s thoughts in one’s own mind). He argues that such a correlation is “simply not admissible” as an explanation because we would remain in the dark about why a sudden upsurge in dopamine causes thought insertion rather than something else. To show why thought insertion comes about, Frith thinks, we need a cognitive story which shows us how it is caused by failures of normal subpersonal processing.