It seems to me that society -- at least the one I live in -- accepts and even demands the presentation of different (artificial) "selves", that is, simulations of the self, rather than constraining the self to be a unitary subject. The law, mentioned below, likes a unified self because that is the self which can be made to suffer and obey; it's real enough for that. Otherwise, in many ways, an authentic unitary subject is not allowed to arise.
kenneth.mackendrick at utoronto.ca:
> Sorry, I didn't address this point... No social constraint can enforce
> unification upon subjectivity (all such attempts, of course, are violent). The
> idea of unity is an illusion - pure fantasy. Legal systems might assume that we
> are unified, and they might act like we are unified, but let's not be fooled,
> the legal system is no more unified than the subject upon which it seeks to
> imprint its right.
Nevertheless we experience things that way -- at least I do. So that is very strong evidence for the unity of the subject, for at least some subjects, since what the subject is experiencing is itself, directly, through which it's "connected" by identity. On the other hand, the argument for the disunity of the subject is rhetorical, since it can't be experienced directly (the "pieces" of the subject, so to speak, would have to achieve at least a temporary, partial unity to experience the disunity of the whole, after having constructed a notion of unity to compare it to). As such, it is subject to the well-known fallibilities and limitations of perception, definition, objectification, and language.
I'm trying to imagine how some sort of disjointed set of subject-components could be deluded into a direct experience of unity, but it isn't easy, even supposing brains in vats of interesting drugs. Moreover, a disunited self would seem to be disadvantageous to survival even if it could be achieved on the scale of a mammalian body, and hence likely to be eliminated by the process of natural selection and evolution. Of course, if one is going to throw out direct experience, getting rid of evolution, physiology, the body, etc. should be fairly easy in spite of their aesthetic and practical attractions.