A Case in Which Two Persons Exist in One Animal
Reid (Mark D.)
Source: Blatti & Snowdon - Animalism: New Essays on Persons, Animals, and Identity, 2016: Part III, Chapter 12, pp. 253-265
Paper - Abstract

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Author’s Introduction

  1. Animalism1 holds that we are each numerically identical to a particular human animal2, and three of its implications are that:-
    1. We existed as mindless embryos3, that
    2. We would continue to exist in an irreversibly comatose state, and that
    3. If one's cerebrum were transplanted4, the recipient would have all of one’s memories and character traits but not be oneself. According to animalism5, one would remain the decerebrate human animal6.
  2. One might suppose that a case involving the gradual transformation of a human person into a nonhuman person, such as a chimpanzee, would be a counterexample to animalism7, since the result would be a different animal but arguably the same person as the original human person. But animalism8 opposes the traditional view that there are psychological conditions for a person’s survival ("Snowdon (Paul) - Persons, Animals, and Bodies", 1995: 73). Moreover, species change, as well as teletransportation9 and the erasure of all of a brain’s psychological contents are conceivable but purely hypothetical and thus weak counterexamples to animalism10.
  3. Better counterexamples to animalism11 are actual cases or realistic but hypothetical cases. Actual cases include
    1. Split-brain12 patients ("Nagel (Thomas) - Brain Bisection and the Unity of Consciousness", 1979; Snowdon, 1995),
    2. Dicephalus13 ("McMahan (Jeff) - The Ethics of Killing: Problems at the Margins of Life", 2002; "Blatti (Stephan) - Animalism, Dicephalus, and Borderline Cases", 2007), and
    3. Dissociative identity disorder (DID14) with multiple personas ("Olson (Eric) - Was Jekyll Hyde?", 2003).
    McMahan and Blatti also consider realistic hypothetical cases of dicephalus15, and Olson considers realistic hypothetical cases of DID with two personas.
  4. In this chapter, I present a realistic but hypothetical counterexample to animalism16 in which two persons exist in one animal. This example is an actual possibility, as it requires only presently available techniques. It asks us to consider the administration of anesthesia to only one hemisphere at a time, so that when one hemisphere is unconscious, the other alone is conscious and free to exercise exclusive control over the human animal17. If applied to one hemisphere after the other in succession, this technique would cause there to be two fully independent hemispheres, each of which could be conscious on alternating days. This case could produce two persons, one per hemisphere, without changing the number of animals. Animalism18, however, denies that this is possible.
  5. The logic of the argument against animalism19 based on this example is as follows.
    1. If each of the two persons were identical to the animal, they would be identical to each other, but they are not.
    2. Because each is a person with an equal claim to be identical to the animal, neither is identical to it.
    3. Because they are identical to no other animal, they are not identical to any animal, which means that it is unlikely that any person is identical to an animal.
    4. Even if only some of us are not identical to animals, animalism20 is false.
  6. Animalists21 and their opponents can agree about the particular mental and non-mental facts of my case but disagree about the number of persons. And the animalist22, it seems, must resist the claim that there are two persons23, but I will show that this is implausible.

  1. Introduction
  2. Duplication24 Objections
  3. A Case in which Two Persons Exist in One Animal
  4. Features of Personhood
  5. Objections

Editors’ Introduction25
  1. Mark D. Reid begins Chapter 12 by surveying what he calls counterexamples to animalism26 which 'involve duplication27', and he concludes that the standard ones are 'inconclusive'. Reid proposes a new potential counterexample, which he urges us to regard as 'conclusive'.
  2. His extremely ingenious and novel case in effect combines brain splitting (with a severed corpus callosum) plus a process called 'Intra-carotid Amytal Procedure', in which one cerebral hemisphere is in effect disabled by the selective injection of some substance leaving the other hemisphere capable of operating. Reid envisages that what happens is that on one day one hemisphere is disabled and then on the next day the other hemisphere is disabled, and so on. This is envisaged as happening from birth (or even earlier). Reid's claim is that the best description of the result is that there are two distinct persons created in a single animal, whom we might call 'Lefty' and 'Righty'. Each sleeps28 during the day the other is awake29.
  3. In his paper Reid carefully develops and evaluates the issues that are involved in this case. Looked at in a general way there are two big questions the imagined case raises.
    1. The first concerns the overall logic. Suppose we agree with Reid's description of what has happened, namely the creation of two persons in a single (human) animal. Is that a serious problem for animalism30? This issue arises for the argument developed in "Campbell (Tim) & McMahan (Jeff) - Animalism and the Varieties of Conjoined Twinning", and so we shall not spell it out again.
    2. The second issue is whether Reid's description of what this case involves is correct. We need to remind ourselves that, if we think about the case in terms of what is happening to the single human animal31, then we have to count it as involving a single functioning entity, the animal, which is being damaged by a complex surgical procedure. Having to think that way about the animal, it seems fair to say, must have some weight in deciding how we are to describe it in terms of 'persons' and 'subjects'.
  4. However, this new case merits careful scrutiny.

In-Page Footnotes

Footnote 6: Footnote 23: Footnote 25: Taken from "Blatti (Stephan) & Snowdon (Paul), Eds - Animalism: Introduction".

Footnote 29:

Text Colour Conventions (see disclaimer)

  1. Blue: Text by me; © Theo Todman, 2020
  2. Mauve: Text by correspondent(s) or other author(s); © the author(s)

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