Multiple personality is one such problem case, because prima facie it raises the possibility of a single human body constituting more than one persons during its life-history. It challenges the commonly held view of a one-body, body-person relation. The phenomenon of multiple personality, however, has received little critical attention by philosophers. In one of only a handful of articles on multiple personality published in philosophical journals since 1940, Kathleen V. Wilkes attributes this neglect to a lack of a steady consensus in the psychiatric community as to the scientific respectability of the diagnosis and its proper method of treatment (Wilkes [1981]).(2) If the psychiatrists can't get it straight, how can philosophers responsibly discuss its philosophical implications?

However, the dearth of philosophical discussion may also be due to certain assumptions that philosophers have about the meaning of 'person' and 'personality' and how these terms are used in the analysis of multiple personality. David Wiggins, for example, hold that the statement (K), "Dr. Jekyll and Mr. Hyde were the same man but not the same person or personality" (Wiggins [1980], p. 29) is a case of ambiguous reference in which 'Dr. Jekyll' and 'Mr. Hyde' have ... to be read twice over in (K) to make it come out true, first as standing each for a man (this individual is the same man as that individual), the second time as standing for a certain kind of character or personality. (These personalities, not these men, are different.) (Wiggins [1980], p. 37)

Wiggins claims that 'the example represents an impulsive attempt to postulate philosophically defined schizophrenia without going the whole way and postulating two men sharing one body, each taking his turn to control it' (Wiggins [1980], p. 37). Wiggins thus assumes that in the context of multiple personality, 'personality' refers to a kind of character rather than to a distinct individual, i.e., a person. And there is nothing philosophically startling about persons manifesting many different characters or personalities in this sense. One's 'character' may change depending on whether one is at home or at school, at work or at play, in a bad or good mood, with friends or enemies . . . Philosophers like Wiggins thus do not view multiple personality as ever challenging the one-one, body-person relation.

In this paper, I examine whether this assumption about the use of the terms 'person' and 'personality' in discussions of multiple personality is correct. In particular, I analyze Morton Prince's discussion of multiple personality in his seminal work, The Dissociation of a Personality, and consider whether multiple personality is a bona fide case of two or more persons sharing one body, each taking his or her turn to control it.

At the start of The Dissociation of a Personality, Prince appears to use the terms 'person' and 'personality' interchangeably and thus to suggest that the same human body can give rise to a plurality of persons. He writes:

"Miss Christine L. Beauchamp, the subject of this study, is a person in whom several personalities have become developed; that is to say, she may change her personality from time to time, often from hour to hour, and with each change her character becomes transformed and her memories altered. In addition to the real, original or normal self, the self that was born and which she was intended by nature to be, she may be any one of three different persons. I say three different, because, although making use of the same body, each, nevertheless, has a distinctly different character; a difference manifested by different trains of thought, by different views, beliefs, ideals and temperament, and by different acquisitions, tastes, habits, experiences and memories. Each varies in these respects from the other two, and from the original Miss Beauchamp. Two of these personalities have no knowledge of each other or of the third, expecting such information as may be obtained by inference or second hand, so that in the memory of each of these two there are blanks which correspond to the times when the others are in the flesh. Of a sudden one or the other wakes up to find herself, she knows not where and ignorant of what she has said or done a moment before. Only one of the three has knowledge of the lives of the others, and this one presents such a bizarre character, so far removed from the others in individuality that the transformation from one of the otherpersonalities to herself is one of the most striking and dramatic features of the case. The personalities come and go in kaleidoscopic succession, many changes often being made in the course of twenty-four hours. And so it happens that Miss Beauchamp, if I may use the name to designate several distinct people, at one moment says and does and plans and arranges something to which a short time before she most strongly objected, indulges tastes which a moment before would have abhorrent to her ideals, and undo or destroys what she had just laboriously planned and arranged." (Prince [1906], pp. 1-2) (emphasis added)

What are we to make of this? Are 'person' and 'personality' synonymous? Is a person different from a personality? Does the body of Miss Beauchamp constitute three distinct 'people' or only three different 'characters' or 'personalities'? In short, what do we mean and what did Prince mean by 'person' and 'personality'?

Before analyzing what Prince meant by these terms, it is important to note that the terms 'person' and 'personality' are not univocal and that they share three common meanings.

The first meaning common to the terms is when they serve to designate the species or those specific characteristics which account for an entity's being a person as distinguished from an animality, vegetability, or materiality. In this sense, which I will call the 'Speci Meaning' of 'person' and 'personality', all persons are characterized by personhood or personality.

The second common meaning of the terms, which I will call their 'Appearance Meaning', may be understood by comparing the definition of 'person' as 'a character sustained or assumed in a drama or the like, or in actual life; part played; hence function, office, capacity; guise, semblance' with the definition of 'personality' as 'the mask or appearance which a man presents to others' (Oxford English Dictionary, 'Person' and 'Personality') (cf. Lawrie [1974]). This 'Appearance Meaning' suggests that there is something behind the 'guise' or 'mask' that has to do with the reality, rather than the mere appearance of the person or personality concerned. It also entails that a human being can have or present many different persons or personalities, and that a person-type or personality-type may be common to many different people. Wiggins' second reading of (K) invokes the 'Appearance Meaning' of the terms. Other statements employing this second meaning include, 'Jones has a different personality than he had some years ago', 'Jones is a different person than the person whom I used to know', and 'Jones has a "James Bond" personality or is a "James Bond" type of person'.

The third meaning common to 'person' and 'personality', which I will call their 'Reality Meaning', is when they are used to designate the existence, individuality, and identity of persons and personalities. 'Person' in this sense means 'the actual self or being of a man or woman; individual personality' (Oxford English Dictionary, 'Person'). Correspondingly, 'personality' means 'a personal being; a person; personal existence; actual existence as a person; the fact of there being or having been such a person; quality or assemblage of qualities which makes a what he is as distinct from other persons; distinctive or individual character, especially when of a marked or notable kind' (Oxford English Dictionary, 'Personality'). Person or personality in this sense is what makes a particular persons or personality what she is and what differentiates her from all other persons or personalities. In contrast to the 'Appearance Meaning' of the terms, persons and personalities in the third sense are unique; they are the realities behind the guise or mask. To be a person is to be a personality; to identify and individuate a person is to identify and individuate a personality.

Throughout his work, Morton Prince appears to use the terms 'person' and 'personality' in their 'Reality Meaning' sense. However, in the end, Prince believed that the multiple persons or personalities which developed in Miss Beauchamp were personalities in the 'Appearance Meaning' sense of terms. Prince distinguished the 'Real Miss Beauchamp' from the other personalities, where the other personalities were 'false' personalities or 'semblances' of persons in the 'Appearance Meaning' sense of the term. While they were not simply masks, roles, or characters assumed by the Real Miss Beauchamp, they were, according to Prince, 'artificial', and should be distinguished from the one, true Miss Beauchamp.

Before looking at Prince's reasons for rejecting the idea that multiple personalities are genuine cases of a single human body constituting more than one person or personality in the 'Reality Meaning' sense of the terms, some reason why one would construe the phenomenon in precisely that way should be considered. Kathleen Wilkes [1981] succinctly presents the case for a plurality of persons or a one-many, body-person relation.

First, the four personalities of Miss Beauchamp (BI, BII, BIII or Sally, and BIV) fail the Lockean memory or continuity of consciousness criterion of identity. There are no symmetrical or transitive memory relations between the personalities.

Second, the personalities have radically different psychological, character, and personality traits. They differ in outlook, moods, ambitions, tastes, and habits. In addition, as subsequent testing of other multiple personality subjects revealed, the personalities demonstrate significantly different reactions to repeated EEG tests that look for alpha and theta wave frequency and amplitude, or the conditions under which alpha activity is blocked (e.g., eye opening). In one particular testing, four different personalities had patterned differences on GSR (galvanic skin response) tests to emotionally laden words; their VER (visual evoked response) to light flashes differed systematically; tests of paired-word learning showed some transfer of learning between one of the personalities to the other three, but no transfer among the other three, and none from any of them to the one that did show transfer (Ludwig, Brandsma, Wilbur, Bendfelt, and Jameson [1972]).

Third, each personality was well-rounded and complete. An uninformed outsider would have found a relatively normal individual no matter which personality was 'out'. It should be noted, however, that in other cases (e.g., Sybil, Jonah) the personalities were not as complete and well-rounded as those of Miss Beauchamp (Schreiber [1973]; Ludwig et al. [1992]). Instead, they seemed designed with specific abilities to accomplish particular kinds of tasks and deal with particular kinds of life situations.

Fourth, each personality satisfied many of the commonly used conditions to identify persons. Each personality was rational, acted intentionally, had command of a language, had conscious and self-conscious experiences, and was an object of moral treatment.

Fifth, from the first-person perspective, i.e., what it is like to be someone from the inside, each personality considered herself separate from the others and was concerned only with her own existence and threatened extinction. It was no consolation to any of the personalities to be promised that she would survive in some form, or to some degree after a merger of streams of consciousness.(3)

Finally, Miss Beauchamp's plurality was synchronic as well as diachronic. Sally not only alternated with the other three personalities but co-existed with them as a second consciousness. She was aware of the actions and thoughts of BI and BII and was even able to act when BI or BII was the primary consciousness. Manifestations of Sally as a concomitant consciousness would take the form of automatic writing, instigation of aboulia, obsessions and imperative impulses affecting the primary consciousness, accurate, rational reports of what the primary consciousness did while the primary consciousness was in a state of delirium, and reports about dreams which were forgotten by the primary consciousness. There were also 'wars of wills' between Sally and the other personalities (Wilkes [1981]).

Wilkes ultimately rejects these arguments for a plurality of persons. Her justification for doing so, however, does not rely on any distinction between the different meanings of 'person' and 'personality'. She does not believe that the multiple persons or personalities of Miss Beauchamp are merely 'semblances' in the 'Appearance Meaning' sense of the terms. The multiple persons or personalities, according to Wilkes, would count on physical and psychological grounds as distinct individuals in the 'Reality Meaning' sense of the terms.

Instead, Wilkes's argument against a plurality of persons invokes moral and social concepts of person, which, she claims, 'presuppose and are built around ... [the fact that] ... practically all the time, with extremely rare exceptions, we have the fact of a one-one relation between person and body' (Wilkes [1981], p. 343). She believes that there are strong normative pressures from our moral and social systems of belief to treat Miss Beauchamp as a single person and that these considerations, as opposed to the physical considerations, should 'carry the day': we should deny the status of personhood to BI, BIII, and BIV.

Thus, she argues: the various personalities were not counted as persons at all; despite the vocabulary used to describe them, despite the fact that each could be blamed or praised for her own activities, but not for those of others. For Prince had little moral compulsion in committing what to BI or BIV seemed like murder; fond as he often was of Sally, he had no hesitation in sending her back to the limbo from which she came, overriding her (often eloquent and moving) protests.

Presumably his attitude can not be made wholly consistent; to blame or praise BIV one day, to work to extinguish her the next, is hard to justify strictly. It is interesting to consider his attitude before BII appeared. When BIV arrived, he thought for some time that she might be 'the real Miss Beauchamp', and worked hard to suppress BI and Sally; he allowed that this was, as far as BI was concerned, her 'annihilation' and 'psychical murder' (Prince [1906], p. 248). Yet it is clear that he did not seriously regard himself as a murderer--there is no analogy with ordinary murder, nor even with abortion or killing in self-defense, so BI can not have been considered a true person after all, despite the 'murder' rhetoric.

Correspondingly, once BII had appeared, he set out to 'kill' BIV as hard as he had tried to 'kill' BI. Thus none of the post-1983, pre-1904 personalities was in fact regarded as a person at all, inasmuch as each was denied the basic right to life. Hence, it appears that the normative constraints on what it is to be a person ruled out the entire trio of Sally, BI and BIV (Wilkes [1981], pp. 344-5).

Wilkes, however, has confused the moral and social concepts and laws of persons with the physical concept and laws of persons--considerations clearly distinguished by Prince. That Sally, BI, and BIV were not 'true' persons by Prince's standard has nothing to do with any moral notion of persons believed by Prince. Sally, BI, and BIV were 'false' persons, according to Prince, because they were artificial creations that violated the nomological basis of the psychological, biological, and physiological concept of person. The 'normative' notions at work are the laws of psychology, biology, and physiology, not morality. Thus, in discussing whether there is a real or normal self, Prince asserts:

"Again, approaching the subject from a purely psychological point of view, it has been held that of the various possible selves which may be formed out of the 'mass of consciousness' belonging to any given individual, there is no particular real or normal self; one may be just as real and just as normal as another, excepting so far as one or the other is best adapted to a particular environment. If the environment were changed, another self might be the normal one. But the psychological point of view is too limited. What test have we of adaptation? There is a physiological point of view, and also a biological point of view, from which personality must be considered. A normal self must be able to adjust itself physiologically to its environment, otherwise all sorts of perverted reactions of the body arise (anesthesia, instability, neurasthenic symptoms, etc.), along with pathological stigmata (amnesia, suggestibility, etc.), and it becomes a sick self. Common experience shows that, philosophize as you will, there is an empirical self which may be designated the real normal self. However, I shall put aside this question for the present and assume that there is a normal self, a particular Miss Beauchamp, who is physiologically as well as psychologically best adapted to any environment. This self should be free from mental and physical stigmata (suggestibility, amnesia, aboulia, anesthesia, etc.), which commonly characterize the disintegrated states making up multiple personality. Such as self may be termed the real self, in the sense that it is not an artificial product of special influences, but the one which is the resultant of the harmonious integration of all the processes, both physiological and psychological of the individual. Any other self is a sick self." (Prince [1906], pp. 233-4)

In contrast to Wilkes, Prince believed that 'person' or 'personality' in the 'Reality Meaning' sense is a natural kind term, that there are psychological, biological, and physiological laws of what it is to be a person or personality, and that these laws determine the extension of the term.(4) Sally, BI, and BIV are ruled out as persons or personalities in the 'Reality Meaning' sense because, despite psychological appearances, they violate some natural laws of personhood. Evidence of some violation is that they are all 'sick' selves.(5)

Prince's distinction between a real person and an artificial or 'false' person, however, is not based solely on his observations of multiple personalities. Throughout his work, he points out various causal factors ('special influences') that can lead to the formation of artificial persons, and he states that these artificial persons have many of the same characteristics as those found in multiple personalities, e.g., extreme suggestibility and amnesia. Prince states:

"Post-hypnotic phenomena ... are manifestations of a doubling of consciousness, artificially induced, of a kind to form two more or less independent mental systems. The independent activity of each system produces the phenomena. But such phenomena, as ordinarily brought about, are not spontaneous, but the result of artificial interference; they are of consequence psychologically in that they show the ease with which even normal minds may be split in two." (Prince [1906], pp. 57-8)

Prince claims that such hypnotic states represent minor or undeveloped forms of personalities, which can develop into a complex synthesis of psychical factors (memories, moods, etc.) and embrace a wide field of consciousness. He holds that when this occurs, we have what to all intents and purposes is a complete personality. It mayehave its own group of memories, with amnesia for the original personal synthesis, and its own peculiar reactions to the environment (moods), thus differing in memory and moods from the original self. It is conveniently termed a second or third personality. (Prince [1906], p. 475)(6)

Other causal factors that may lead to the dissociation or disintegration of the person are physical injuries and mental or emotional shock.(7) It is also worth nothing Prince's consideration of Janet's studies on 'hysterical amnesia', since Prince's remarks are relevant to the memory criterion of personality identity, which might be used to support the claim that there are multiple persons associated with one body in cases of multiple personality. Prince explains that 'from one point of view, it is not amnesia at all, that the lost memories are conserved, but so dissociated from the personal consciousness that they cannot be recalled' (Prince[1906], p. 257).

Thus, in the case of multiple personality, each personal consciousness has in some sense the memories (or memory traces) but is simply unable to recall them. Consistent with this interpretation of amnesia, a memory theorist migh claim that it would be impossible that in this minimal sense of 'having' memories, persons constituted by different bodies could have the same memories.

In contrast to Wilkes's view, Prince's distinction between artificial and natural persons provides the correct basis for interpreting the phenomenon of multiple personality. Prince, in fact, thought that 'disintegrated personality' was a better descriptive term than 'multiple personality', since 'each secondary personality is only part of the normal whole self. No one secondary personality preserves the whole psychical life of the individual' (Prince [1906], p. 3).

In addition, Prince clearly distinguish cases in which the artificial or natural person ceases to exist (the destruction of the person) from cases of multiple personality (the disintegration of the person). He writes:

"secondary personalities are formed by the disintegration of the original normal personalities. Disintegration as thus used must not be confused with the same term sometimes employed in the sense of degeneration, meaning a destroyed mind or organically diseased brain. Degeneration implies destruction of normal psychical processes, and may be equivalent to insanity, whereas the disintegration resulting in multiple personality is only a functional dissociation of that complex organization which constitutes a normal self. The elementary psychical processes, in themselves normal, are capable of being reassociated into a normal whole." (Prince [1906], p. 3)

Moreover, as indicated earlier, Prince believed that there are degrees of disintegration which give rise in varying degrees to artificial persons or personalities, i.e., to the appearance of a plurality of natural persons or personalities. The simplest form of an artificial person appears in highly synthesized 'automatic' or hypnotic phenomena, e.g., through automatic writing or states of hypnosis (Prince [1906], p. 4).

"In more fully developed forms," Prince asserts, "the second personalities are identical with the trance states of mediums, like that of Miss 'Smith', studied by Flournoy, and that of Mrs. 'Smead', studied by Professor Hyslop. In such cases the second personality does not obtain a completely independent existence, but comes out of its shell, so to speak, only under special conditions when the subject goes into a 'trance'. The external life of personalities of this sort, so far as it is carried on independently of the principal consciousness, is extremely restricted, being confined to the experiences of the so-called 'seance'. Although such a personality is complete in having possession of the faculties of an ordinary human being, there is very little independence in the sense of a person who spontaneously and voluntarily moves about in a social world, and works, acts, and plays like any human being. It is questionable how far such a personality would be capable of carrying on all the functions of a social life, and of adapting itself to its environment. Hypnotic states, that is, artificially induced types of disintegration, are rarely, if ever, sufficiently complete, and possessed of adequate spontaneous adaptability to the environment to constitute veritable personalities." (Prince [1906], p. 4)

Finally, Prince states: "In the most fully developed forms . . . the disintegrated personality retains that large degree of complexity of mental organization which permitsmplete, free, and spontaneous activity, approximating, at least, that of normal mental life. Though some cases exhibit glaring mental and physical defects, others may, to the ordinary observer, exhibit nothing more than an alteration of character and loss of memory for certain periods of life. Such persons often pass before the world as mentally healthy persons, though physically they may be neurasthenic. But a careful physiological examination will reveal deviations from the normal which show the true character of the alteration. It is to this last category that Miss Beauchamp belongs. In any one of her mental states she is capable of living her social life and doing her daily duties, subject only to the limitations set by poor general health; and, as a matter of fact, each personality leads it own life like any other mortal." (Prince [1906], p. 5)

Prince's remarks show what is wrong with relying on Wilkes's third argument for a plurality of persons, namely, that each personality was well-rounded and complete, and that an uninformed observer would have found a relative individual no matter which personality was 'out'. Prince admits that to the ordinary observer, 'Such persons often pass before the world as mentally healthy persons.' His point, however, is that we should not confuse the appearance of natural persons with the reality of natural persons, and that we should appeal to psychology, biology, and physiology, not ordinary experience, to distinguish them. Miss Beauchamp's personalities suffer from severe mental and physical defects: aboulia, impulsions, neurasthenia, amnesia of actions and thoughts, violent mood and character changes, abnormal suggestibility, and severe limitations in their ability to adapt to their environment. Normal, real persons do not suffer from these defects, or at least not all of them.

After Prince's synthesis of the personalities and his discovery that the awakened BII is the 'Real Miss Beauchamp', the normal, real Miss Beauchamp does not suffer from neurasthenia, hallucinations, impulsions, obsessions, aboulia, or abnormal suggestibility (Prince [1906], p. 518).

In summary, there is a distinction between natural and artificial persons and the phenomenon of multiple personality should be interpreted as involving two or more persons or personalities that can be individuated only in the 'Appearance Meaning' sense of the terms, i.e., as semblances of real persons or personalities. This distinction is not drawn for social or moral reasons but for psychological, biological, and physiological reasons. Artificial persons behave in ways that violate the nomological basis of the 'Reality Meaning' sense of the term 'person' and therefore fall outside its extension.

Here, there is substantial agreement between Prince and David Wiggins. Wiggins distinguishes artifacts, e.g., chairs and cups, from natural kinds, e.g., human beings and persons, on grounds that the former are not identified under concepts that are nomologically conditioned. Similarly, Prince distinguished artificial persons from natural persons on grounds that the former violate the nomological regularities that underlie the concept of person. Both maintain that functionalist psychology is insufficient to account for our concept of person. Finally, both argue for a one-one, person-body relation based on natural laws of psychology, biology, and physiology.(8)

(1) See, for example, philosophical discussions of brain transplants (Roland Pucetti [1969]; Bernard Gert [1971]; George Rey [1976]; Shaffer [1977]); body-splitting (R. M. Gale [1969]; David Wiggins [1976]); replication (Derek Parfit [1986]); and commissurotomy (Thomas Nagel [1971]; Roland Puccetti [1973]; DeWitt [1975]; Puccetti [1976]; Charles E. Marks [1981]; Puccetti [1981]).

(2) Wilkes points out that in the mid-nineteenth century, when multiple personality was considered a genuine--and fascinating--diagnostic category, many cases were reported. However, with a prevailing skepticism in the mid-twentieth century, alternative diagnoses (e.g., schizophrenia, psychosis, cerebral trauma) were made, and virtually no cases of multiple personality were reported. Wilkes also cites studies by Taylor and Martin [1944], Orzech, McGuire, and Longnecker [1958], and Congdon, Haig, and Stevenson [1961], which suggest that multiple personality may be extreme form of role-playing and therefore should not be considered a separate diagnostic category. Finally, hypnosis, though traditionally employed as a method of therapy, has been suspected as actually causing, or at least solidifying, the condition (Harriman [1942, 1943, 1947]; Bowers and Brecher[55]; Orzech, McGuire, and Longnecker [1958]; Gruenewald [1971]).

(3) The personalities in the actual Beauchamp case apparently have a much different reaction than that of Derek Parfit to the issue of survival as opposed to personal identity.

(4) The view that natural kinds are nomologically grounded has been proposed by Hilary Putnam [1970] and Saul Kripke [1972], and can be traced back to Leibniz and Aristotle. On this view, the determination of a natural kind depends on the existence of lawlike principles that collect together the actual extension of the kind around an arbitrary good specimen of it and that determine the characteristic activity, development and history of members of this extension (cf. Wiggins [1980], pp. 77-86, 169-75).

(5) Not every 'sick' self is, of course, an 'artificial' self. Many people, for example, exhibit neurasthenia and aboulia, but that does not make them 'artificial'. Prince was led to the diagnosis of the artificial status of the various personalities in the Beauchamp case through his observation of what may be a unique combination of symptoms exhibited by multiple personalities, his physical and psychological testing of the personalities,consideration of their causal history, and comparison of the phenomena exhibited by the multiple personalities with other dissociative states.

(6) More recent studies of multiple personalities also indicate that hypnosis or suggestion may be etiological factors of the condition. See Harriman [1942, 1943, 1947], Bowers and Brecher [1955], Orzech, McGuire, and Longnecker [1958], and Gruenewald [1971].

(7) Taylor and Martin [1944] list cortical damage, lowered energy levels, severe shock or stress, and severe conflicts as possible etiologic factors of multiple personality.

(8) My own view is that the concept of person is a hybrid concept; it is neither purely natural nor purely artifactual. It is, in part, nomologically conditioned and, in part, determined by social convention. Thus, some issues about persons and their identity, such as whether multiple personality is a case of more than one person sharing a single body, are resolved bynomological considerations. Other issues, such as whether someone who has undergone total, 'philosophical' amnesia or 'brain zap' is the same person, are resolved by social stipulation. For more on this, see my doctoral dissertation, Metaphysical and Cultural Aspects of Persons, Columbia University (Ann Arbor; University Microfilms, 1991).

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