- The last chapter attempted to undermine the reliability of the judgement that MPD1 cases are instances of 'serial' pluralism. In this chapter I want to consider whether there are plausible cases of simultaneous, or synchronic, pluralism. This means engaging with the problem of how to describe what is generated by so-called split-brains, and also with imaginative extensions of such cases in which the degree of destructive and constructive intervention in the mental functioning of the subject is greater than in actual examples. The distinction between serial and synchronic does not in fact correlate quite so tidily with the different cases. Believers in MPD2, influenced as they are by the stories that the subjects are prone to tell, often assent to judgements which commit them to synchronic pluralism. I shall, though, carry on pretending that things are tidier than they really are.
- In order to impose some order on the discussion I shall divide the suggested examples into two groups.
The reason for dividing the examples up in this way is that it is fairly clear what an animalist5 must say about the former cases, and the intuitive pull of saying something inconsistent with animalism6 is not, I believe, impossible to counter. Whereas, what the correct animalist7 treatment of two-headed examples should be is less clear, and the intuitive pull of describing them as involving two subjects is considerable. Maybe, though, that is not a problem. I shall consider the single-headed cases first.
- In the first we have a normal human being, whose brain is interfered with, to different degrees, apparently producing more than one subject. There are, of course, actual examples of this kind, but imaginary extensions of such processes also need to be considered. In imaginary cases the degree of interventions in the brain can be far more extreme.
- In the second we have animals, perhaps freakish human beings or purely imaginary beasts, which have more than one head. An imaginary example would be the two-headed push-me-pull-me animals described in some children's stories. Another sort of case, this time actual, is what are called 'dicephalic3 conjoined twins4'. The simplest (but not necessarily the most accurate) description is that they are children born with two heads but one body. What should be said about them?
- My method in discussing them is to determine what an animalist8 seems committed to saying, and then to consider whether decisive or strong reasons can be found to reject that answer. I also wish to explore what general approaches to the problem of the unity of consciousness9 will validate the animalist10's claims and whether any such approaches seem defensible or plausible. When reflecting on these types of cases many seem drawn to classifying them as belonging to the [A&~P] category. The question is: is that response well founded?
- Puzzles of Commissurotomy11
- The Animalist12 Treatment
- Unity Requirements
- The Possibility of a Consistent Interpretation
- Other Constraints
- Inferential Conditions
- Unity of Experience Principles
- Some Problems
- What Experience Must Be Like
- Peacocke’s Example
- An Alternative View
- The Alternative Considered
- A Referential Reading
- Conclusions About Split-brains
- Multi-Headed Monsters
- Imaginary Multi-Headed Animals
- Actual Multi-Headed13 Cases
- Inspired by a sense that the patient in a split-brain case is a single, functioning human being, I have argued that we should look with suspicion on the principles of psychological unity14 that have led to a rejection of a singularist account. Such cases do not represent well-founded (A&~P) cases. Nor, I have suggested, do examples of dicephalic15 twins16, or related cases, when realistically and cautiously analysed, provide counterexamples to animalism17.
- The most serious challenge to animalism18, I believe, comes from some alleged (P&~A) cases, and it is the issues raised by them that need to be considered next.
Text Colour Conventions (see disclaimer)
- Blue: Text by me; © Theo Todman, 2020
- Mauve: Text by correspondent(s) or other author(s); © the author(s)