MEDICINE AS METAPHOR IN PLATO©
Joel Warren Lidz, Ph.D.
Published in the Journal of Medicine and Philosophy
Greek Characters have been omitted
Greek philosophy can be adequately understood only if one recognizes that it arose in conjunction with ancient medical theory, with which most educated Greeks were familiar (Carrick, 1985, p. 26; Edelstein, 1967, p. 361), and reflects that relation in large measure. Whereas Werner Jaeger (1943, p. 3) held that: "Socrates' doctrine of ethical knowledge ... would be unthinkable without the medical model," Ludwig Edelstein argued that "in antiquity philosophy influenced medicine rather than being influenced by it" (1967, p. 350). James Longrigg (1963) has taken the middle road by arguing for a mutual influence correctly, I think. As for Plato, Julius Moravcsik has recently noted that: "One of the ways in which Plato explains his ethical views is by drawing an analogy between the healthy body and the good human" (1992, p. 100). My purpose in this essay is, by exploring Plato's use of this and related analogies, to consider the effect of ancient medicine on his ethics. I proceed by considering parallels between Greek medical theory and some basic concepts of Platonic ethics, such as eudaimonia, soul, nature and convention. Before doing so, however, I shall briefly outline some of the relevant historical antecedents of Plato's thought.
II. THE HISTORICAL CONTEXT
A central concept common to both Greek metaphysical and medical thought is that of a balance between opposing powers. In what is arguably the earliest philosophical epigram to come down to us, Anaximander relates coming-to-be and justice: "the source of coming-to-be for existing things is that into which destruction, too, happens, according to necessity, for they pay penalty and recompense to each other for their injustice according to the assessment [or "ordering"] of time" (Kirk and Raven, 1983, p. 118).
In the early fifth century B.C., the physician, Alcmaeon of Kroton, likewise made polarity central to his theory, claiming that most things pertaining to human affairs come in opposing pairs of powers which impart their qualities into the whole they enter. Wholes were viewed as mixtures of opposites, and health as an equilibrium between powers, with the consequence that a patient was conceived of as similar to a front between two warring forces, much as we today think of viruses and antibodies locked in struggle (Moline, 1981, p. 11). According to Aetius (first or second century, A.D.), the basic principles promulgated by Alcmaeon were as follows: the body is a complex of powers; the health of an organism depends on a dynamic equilibrium between opposing powers; disease results from the disruption of such equilibrium; though an internal condition, such disease can be caused by external influences; health exists when the qualities or powers are "blended in proper proportion" (Diels-Kranz, 24B4.). The Hippocratic text, On Ancient Medicine, similarly states that mixture and measuredness of opposing elements are of the essence of health (Ch. 14), that nothing is purely hot or cold, etc., and that so long as elements are mixed properly there is no harm, but when standing alone, harm results (Ch. 16; cf. Aristotle, Topics, 145b8; Physics, 246b5). The papyrus Anonymus Londinensis mentions twenty medical authorities, all of whom subscribe to the idea.
That Plato was influenced by these metaphysical and medical metaphors is clear, though metaphors which underlie philosophical theories are not normally the subject of explicit discussion by those who employ them, and Plato was no exception. Such "root" metaphors serve to illuminate a range of phenomena, opening a horizon for theorizing, but themselves remain undiscussed. Of course, the greater the frequency of Plato's use of medical metaphors, and the greater the number of parallels between the ideas of his physician-predecessors and his own (especially those connected to philosophy as care of the soul), the more one can feel justified in postulating a connection. At least four sorts of evidence for a connection between Greek medical theory and Plato might be mentioned:
(1) Anonymus Londinensis (believed to be based in part on the Iatrika of Aristotle's pupil, Menon) mentions Plato as one of twenty medical authorities who hold that our bodies are composed of a combination of elements, and who explain diseases as due to the elements (Tracy, 1969, p. 25; cf. Timaeus 82a; Aristotle, Physics 246b4).
(2) Plato uses many terms also employed in medicine, including eidos (usually translated as "Form" or "Idea"), which occurs in the Hippocratic treatises Nature of Man (Ch. 12), Humours (Ch. 1) and Airs, Waters, Places (Ch. 3). Other terms common to doctors and philosophers include: powers; equilibrium; blending or mixture; measure; excess; responsiveness; harmony; habit; disposition; right proportion or time; to strive after; and proportion. Jaeger noted that Airs, Water, Places differentiates character types on the basis of climate and other external influences, and uses the term "aggressive" to describe the peoples of Europe. In the Republic, Plato appropriated that term to describe the characteristic temperament of the Guardian class.
(3) As noted earlier, Plato conceives of philosophy as a kind of care of the soul. At Alcibiades I (146e), Socrates says that the soul that is to live uprightly must hold fast to knowledge of the good, "just as a sick man does to a doctor," and (as discussed below) many of his ideas for such treatment parallel the methods of treatment of Hippocratic authors.
(4) Plato makes liberal use of medical analogies, such as that comparing justice and injustice to health and illness, respectively (Timaeus 42b), while physical health without justice (i.e., a well-ordered soul) is not good (Laws 661a). Phaedrus 270b compares the skill of medicine to that of philosophical rhetoric. Plato also draws analogies between body and soul, as well as between soul and city, in such a way as to reflect somewhat ancient medical theories. Politics, e.g., is described as the craft of tending the soul, while the craft of tending the body has two parts: gymnastics and medicine. In politics, the counterpart of gymnastics is legislation, while justice corresponds to medicine. Justice and legislation care for the soul. Each of the four skills (medicine, gymnastic, legislation and justice) provides care for the soul or for the body, "with a view to what's best" (Gorgias 464c). Below, I consider how Plato assimilates medical concepts to his ethics.
III. MEDICAL METAPHORS IN PLATO'S ETHICS
Health as a Condition
Medicine proves to be an especially apt metaphor for Platonic ethics, inasmuch as it serves to remind us that, as with our body, the condition of our character requires development and care, and that each of us must choose whether and to what extent we wish to develop and care for our character: "[For Plato] the responsibility for carrying out a program of mental and physical hygiene rests squarely with each person.... One can be held accountable for remedying whatever defects of one's birth or childhood come to one's attention as an adult citizen" (Carrick, 1985, p. 27f.). Plato's ethics emphasizes prevention rather than cure; it proposes an intellectual regimen for the production of a certain êthos, not merely a set of imperatives as to one's obligations.
Both body and soul assimilate elements of the physical and ideological environments with the result that they are thereby affected in a certain manner. Since just actions make for a just individual, much as healthy activity makes for a healthy individual (Rep. 444c; cf. Aristotle, Topics 110a19), it follows that one's moral condition as an adult is determined largely by one's moral rearing during childhood. Morals must therefore be carefully cultivated from childhood (Rep. 590e-591a). Failure to provide such a course of moral education is likely to create difficulties, since by the time one has become an adult, ones' character is already largely determined. A successful moral upbringing produces a character which is resistant to bad influences (Rep. 367a), just as "a man in health and strength can drink any water that is at hand without distinction" (Airs, Waters, Places, ch. 7). In short: our moral sense does not exist in a temporal vacuum, but "grows like a vine tree" (Pindar) requiring constant attention from childhood. No moral theory offered to adults can substitute for that sort of ongoing attention.
A second implication of the medical model is that our moral condition, like our health, is an inward condition. Once construed in this way, morality can no longer be considered simply a matter of how one's actions affect others. Rather, our proper area of moral concern is our inner Self (Phaedrus 229e-230a) and so ethics must focus on how we relate to ourselves (for example, in terms of self-control and self-perception; i.e., our measuring of ourself against an ideal standard which we have set for ourself). Rather than searching for a single lawlike norm for action (such as Hobbes' first law of nature, Mill's greatest happiness principle, or Kant's categorical imperative) which might be used to determine the rightness or wrongness of one's actions, the medical model leads instead to a focus on character, on those traits which would be conducive toward the production of a certain inward condition (personality type). Thus the medical metaphor already contains within itself the basis for an agent-centered, rather than act-centered, theory.
A third consequence of focusing on character as an inward condition rather than on action is that observing whether one's present actions are conducive to health is not enough in order to know whether one's (physical or moral) condition is healthy, since one can engage in healthy or moral actions without knowing that they are such, and/or for the wrong reasons. One's actions may (on occasion) be conducive of somatic health, though one's body may not be healthy. Analogously, one's actions may be consistent with a good moral character even in the absence of such. Clearly, it is preferable that one's moral acts be reflective of a truly moral character, as they will then be more reliably moral.
Apparent vs. Real Health
The health analogy further implies that just as one may believe oneself to be physically healthy and yet not be, the same is true with respect to one's psychic health, i.e., moral condition. (Presumably, the same might be said of the condition of the polis, much as Erich Fromm argued in the The Sane Society.) One of the more important passages which develops this distinction between real and apparent health is that at Gorgias 464a, where Socrates distinguishes between body and soul, and says that each has an apparent and real state of fitness. Corresponding to these apparent and real states of health are apparent and real skills purporting to produce real states of health. Both medicine and justice have pseudo-forms which, while pretending to be the real thing, pander to base desire (i.e., desire not aimed at satisfying those needs which if met will benefit oneself). (A Sophist, one might say, is to philosophy what a quack is to medicine.) Fine cookery, e.g., pretends to know which foods are best for the body by appealing through its good taste and adornment. But medicine (unlike fine cooking) is concerned primarily with needs, not desires. Its interest in desires would seem to bear only upon the extent to which they reflect or come into conflict with known or unknown needs (which may conflict with one's desires). Attempts to satisfy even natural needs such as hunger can lead to counterproductive activity, such as gluttonous behavior--a point made, e.g., in the discussion of the "city of pigs" (Rep. 372d).
The prescriptions of a physician derive their value from being in harmony with what is by nature good for the body that which the body needs to be healthy (i.e., function well) such that it would follow that all persons interested in protecting their health would obey such a prescription. Just as a rational person would prefer to be healthy even when considered unhealthy by everyone else, so it is rational to prefer to be moral regardless of what others think of one's character, precisely because justice is a psychic condition analogous to physical health (cf. Crito, 48a).
Plato rejects the orthodox view of eudaimonia (well-being), which was popularly understood as a condition in which a sufficient number of good things is possessed and enjoyed (cf. Greater Hippias 291d), leading inevitably to the notion that one person's well-being must be purchased at the expense of another's (Adkins, 1960, p. 251). But by viewing eudaimonia as a sort of internal condition, i.e., as a matter of one's character rather than of what one has or does, Plato thereby rejects the conventional view, which sets the good of individuals in competition with one another. One who nourishes himself on wisdom need not compete with others, since the 'amount' of wisdom acquired by one individual does not lessen that available to others. The quest for wisdom and the other virtues can more easily be cooperative than that for material goods or fame, and thus need not imply a Hobbesian "war of all against all."
For Plato, eudaimonia is to the soul as health is to the body -- an idea which anticipates that widely held by psychologists today, according to which mental health consists in integration of ego functions. In the Republic, Plato presents a detailed discussion of the soul as tripartite, having an appetitive, spirited and rational "parts" (or "kinds": eidê). The soul's complexity is such that its "parts" can function at least somewhat independently and stand in direct conflict. Each part is attracted to a different sort of thing: appetite loves material things (439d), spiritedness loves honor, and reason loves wisdom (581b). The body's proper functioning (i.e., health) requires, among other things, the receiving of the sort of nourishment which is by nature salutary, and the soul is similarly nourished by receiving thoughts appropriate for its nature; hence the detailed program of education and censorship in the Republic, which aims at avoiding a disordered arrangement of these parts (442d).
Just as the body's proper functioning depends on the proper functioning of all its organs, so the soul and city depend on the proper functioning of each of their "parts." This comes about, not through the outright suppression of any one part, but through the dialectical testing of the aims of each part. It seems that Plato understands health as the effective functioning of the whole according to nature, as made possible by the effective functioning of each part comprising that whole. One of the primary purposes of moral education is to establish the sort of hierarchy within the soul from which it benefits most, viz., that of an integrated unity. Organs must function well within the organism in relation to each other; individuals within social contexts. One (ideally) seeks a moral condition consistent with what is by nature beneficial for one's whole self, and reason dictates that that part most capable of synoptically apprehending the good of the whole determine the appropriate function of each part. Consequently, medicine, as the science of the body, is properly subordinate to the science of the soul, for "the body is treated by the soul and it is not possible for a soul that is or has been evil to treat anything well" (Rep. 408e; cf. 591c). Human life qua mere life (zoê) exists for the sake of human life qua human (bios), the latter consisting not merely of one's physical condition, but also of one's perceptions of the quality of his or her social relations, intellectual abilities, aesthetic qualities of the physical condition, etc.
In sum: Plato regards the good for an individual (i.e., eudaimonia) neither as a sort of experience or possession (as did the masses), nor as a simple balance of opposing forces (as did the ancient physicians), but as a condition associated with the soul's naturally proper functioning, a condition antecedent to experience and which colors it, just as the body's health colors our experiences and consists in its organs performing their proper, hierarchically determined functions effectively. But his commitment to hierarchy is apparent even in Socrates' examination of his interlocutor, whereby he creates a miniature social hierarchy by putting his interlocutor "in his place." Medicine provides for Plato a model which aids philosophy in understanding its task, while philosophy restrains the pretensions of medicine by reminding us that the physical needs of humans are only part of a much broader context of one's relation both to oneself and to others, as well as by reminding us of the distinction between ends which are really worthy of pursuit and those which are only apparently so.
Medical and Moral Competence
The medical model is predicated on the hierarchical relation between doctor and patient. As with ancient medicine, ancient moral theory presupposes that some are capable of greater insight (i.e., competence) than others. While it is assumed that the doctor's diagnosis is superior to that of a layman, doctors also vary in levels of competence. Since medical and moral competence vary from person to person, it is not true that what is right (permissible) for one person to do is right for all. Persons of greater moral ability, e.g., will under some circumstances be obliged to demand more of themselves than someone of lesser moral understanding, just as a physician's responsibilities are greater than that of a layman when confronted with an injured or sick person. On the other hand, Sophists (like the public) lack the competence of a Socrates to care for people's souls (cf. Rep. 492b). In short, the medical model leads us to transcend the notion of universally obligatory actions in order to ask what each of us as an individual is capable of doing. Thus, a clearcut distinction between obligatory and supererogatory acts is likely to be rejected on this ethical model. Just as different persons' bodies are capable of different degrees of healthy functioning, so one must not expect the same level of moral functioning from all persons, hence the classical distinction between demotic and philosophic virtue. In some cases, e.g., one must expect another to restrain himself only out of fear of punishment.
The ideal of the judicious man served as the exemplar of the moral life for the ancients (cf. Aristotle, 1985, 1107a2). However, just as one must be willing to commit oneself to a program of physical regimen if one wishes to develop physically, so one must be willing to undertake the rigors of dialectic if one wishes to improve morally. But one's willingness to undertake a regimen is itself indicative of one's character and this in turn raises the question of whether one's willingness is itself (at least to some extent) dependent on factors over which one has no control, thus whether there might not be (in Aristotle's terminology) natural slaves -- persons inherently incapable of escaping from Plato's cave.
Morover, just as one's state of bodily health affects the way one reacts to foods, so the condition of one's soul influences the way in which one is affected by thoughts. The body's response to a certain type of food is taken to be an index of its condition; e.g., a painful response to ordinary food eaten in moderation indicates illness, just as one's being repelled by noble thoughts is symptomatic of a diseased soul. As Aristotle writes:
[J]ust as different things appear honourable to boys and to men, it is reasonable that in the same way different things appear honourable to base and to decent people....
[T]o each type of person the activity expressing his own condition is most choiceworthy (Aristotle, 1985, 1176b24).
[T]he good person ... is the measure of things; what appear pleasures to him will also be pleasures.... If what he finds objectionable appears pleasant to someone, that is nothing surprising, since human beings suffer many sorts of corruption and damage. Such a state of corruption is produced by training and practice which result in an inferior character and is difficult to correct, since it is a corruption of the very faculties which would be needed to correct it (1176a16).
Because the condition of one's soul influences the way in which one is affected by thoughts, one's choice of ideals predetermines the degree to which one can benefit from the dialectician's art (much as one's choice of dietary habits influences one's ability to benefit from the medical art). James Wiser makes the point well: "Unlike rationalism's faith in the power of an abstract and universal mind, Platonism acknowledges the concrete existential realities which condition man's search for truth. In short, who one is determines what he can know, and as a result man's escape from the cave of opinion presupposes his prior existential conversion" (Wiser, 1983, p. 59). Health makes it possible to make use of all our human powers in an optimal manner, just as "the good person will be a friend to himself, since he will both help himself and benefit others by doing fine actions" (Aristotle, 1985, 1169a12).
Since the same level of moral functioning cannot be demanded of all, one of the primary tasks of the dialectician qua physician is to determine what level of morality can be reasonably expected in the case of each individual. In the Gorgias (504a), Socrates likens the good rhetorician to a good physician, while in the Phaedrus (271c) he says that: "Since it is the function of words to lead souls by persuasion, one who is to be a rhetorician must know the various kinds of soul" (cf. Rep. 576e). For Aristotle: "education adapted to an individual is actually better than a common education for everyone, just as individualized medical treatment is better" (Aristotle, 1985, 1180b15). Though health is contingent upon the assimilation of appropriate elements from the environment, differences in the bodies of individuals may dictate differences in the appropriateness of the substances assimilated.
IV. LIMITS OF MEDICINE AND MORAL EDUCATION
The medical model suggests that ethics, like medicine, is necessarily inexact, as both depend on highly complex diagnostic procedures, on treatments (or in the case of philosophy, dialectic) which must take into account fine differences between patients (On Ancient Medicine, chs. 9; 12). Moral life cannot, therefore, consist mainly in the conscientious adherence to rules, as such rules are not amenable to absolute determination.
In ancient Greece, the fact that medicine possessed significant inherent limitations was often construed as evidence that it is not a genuine science. Disagreements arose not only concerning the causes of diseases, but also about methodological questions concerning the appropriate type of theory and evidence needed for a correct diagnosis. One of the Hippocratic aphorisms even notes that in medical treatment, "the same reasoning can lead one to take opposite routes" (IV, 9). The ancient physician therefore had to defend medicine against those who would discredit it. Although medicine was considered a science by its practitioners, not all sciences were regarded as exact. The author of On Ancient Medicine readily admits that medicine is inexact: "it is difficult to acquire knowledge so accurate that only small errors are made...." (ch. 9). One should therefore seek success only within realistic limits and avoid treating the worst cases.
Another acknowledged consequence of medicine's inexactitude was that it could have no dogma and cannot do much in the way of providing general advice (Edelstein, 1967, p. 108). (In this respect, Greek medicine is much like Greek religion, which was a matter of activities and myths rather than creeds.) The Hippocratic authors for the most part recognized that generalizations about human nature have exceptions. Epidemics I, 23 includes as diagnostic criteria "the common nature of all and the particular nature of the individual," along with many others. The fact that each individual possesses a "particular nature" means that the therapeutic word must be accommodated to the character and state of mind of the patient (Phaedrus, 271d). Plato's choice of dialogical form (which, one might say, is meant to be a sort of rhetorical medicine, rather than rhetorical cookery) is related to this. The dialogues present us with (among other things) Socrates, an individual, tailoring his speech for specific individuals, unlike a treatise, whose writer addresses any and all in the same manner. One ought not expect the same level of moral functioning from all, as it is contingent to some extent on intellectual ability.
Despite the inherent limitations of medicine, its results seemed somewhat more trustworthy than mere chance, so that the advice of a physician was commonly sought when the presence of illness was acknowledged. Socrates frequently argues that just as we seek the help of an expert when our body is in need of rehabilitation, so we should do the same for our soul. For Aristotle, not everyone can improve the condition of others, "but if anyone can, it is the person with knowledge, just as in medical science and the others that require attention and intelligence" (Aristotle, 1985, 180b25).
It is, of course, not sufficient that the physician be expert in the distinguishing of healthy and unhealthy actions and states; he must also be able to persuade his patient (possibly through deception or even force) to accept treatment which the patient may find objectionable. (This point is driven home at Gorgias 465a, where Socrates must convince Polus that punishment, the moral equivalent of curative medical treatment, is in the offender's best interest.)
If the primary end of medicine is to improve health, then it may be that in some circumstances that end will conflict with certain ideals, such as truth-telling. Physicians may thus find placebos justifiable in some cases, and rulers (i.e., philosopher-kings) may similarly have to resort to rhetorical placebos on occasion (Rep. 459c). Socrates says in the Republic that if falsehood is "useful to people as a form of drug, then we must allow only doctors to use it, not private citizens" (389b). In the modern era, of course, the notion that a minority of persons may possess an expertise regarding ethical and political considerations tends to be identified with such objectionable "isms" as elitism and paternalism. For Locke: "the care of every man's soul belongs unto himself, and is to be left unto himself" (quoted in Wolin, 1960, p. 340). Bentham writes: "Generally speaking there is no one who knows what is for your interest so well as yourself" (quoted in Arblaster, 1984, p. 30). This view implicitly suggests a radical difference between the nature of physical and moral well-being, such that we should expect each individual to possess sufficient understanding to be responsible for his or her own moral, if not physical, well-being -- a view critiqued in Plato's Protagoras and which remains one of the more intractable problems of medical ethics.
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