Recent biomedical theories of depression, and of the symptoms of physical and mental exhaustion that are associated with it, center primarily on chemical imbalances in the brain. They are based on the assumption that pathological low mood states are connected to neurotransmitter deficiencies. Since the 1980s, biomedical depression research has concentrated predominantly on the monoamines norepinephrine and serotonin, and the enhancement of selective serotonin reuptake inhibitors (SSRUI).
1 Serotonin is a molecule that transports signals between the synapses in the brain and that regulates emotions, reactions to external events, and physical drives. Low serotonin levels are generally seen as a symptom of depressive moods, but there is still considerable debate as to whether they are also their cause. SSRUIs were first sold under the trade name Prozac in 1987, and Prozac rapidly became a blockbuster prescription drug. It is still the most frequently prescribed antidepressant to date.
Yet the idea that an imbalance of specific substances in the body causes states of low mood–related exhaustion is not at all new. Indeed, it is to be found in ancient humoral theory. Hippocrates first introduced humor theory to medicine in the fifth century
B.C.E., and the Greek physician Galen of Pergamum (129–ca. 216) further developed the idea. Galen’s version of humor theory was so influential that it remained the dominant medical paradigm until the advent of modern medicine in the nineteenth century.
2 One of the central tenets of this theory is the importance of a balance among the four bodily fluids, or humors: blood, yellow bile, black bile, and phlegm. Within this framework, all illnesses—be they chronic or acute, mental or physical—can be explained by the relative excess or insufficiency of one or more of the four humors. According to Galen, each humor is also associated with specific qualities and with one of the four elements: blood is aligned with warmth and moisture, and the element air; yellow bile with warmth, dryness, and fire; black bile with coldness, dryness, and earth; and phlegm with coldness, moisture, and water. Furthermore, each of the humors is also related to a particular temperament—blood is associated with the sanguine, yellow bile with the choleric, black bile with the melancholic, and phlegm with the placid temperament. Humor theory functions thus to explain not only acute and chronic physical and mental disturbances but also long-term character traits and psychological dispositions.
The balance among the humors was thought to be precarious—it could easily be upset by a surplus or deficit of particular fluids, which could be caused by infections, inflammations, unwise dietary choices, and intemperate lifestyles, as well as by grief and sleeplessness. Acute diseases were mainly associated with disturbances in the quantities of blood or yellow bile, while chronic diseases were generally related to a deficiency or an excess of phlegm or black bile. Consequently, the most common cures administered by physicians until the modern period entailed bloodletting, emetics, the application of leeches, blistering, and purging—all designed to evacuate the body of a humoral excess and thereby to reestablish an equilibrium among the bodily fluids.
In Galen’s writings, we encounter exhaustion primarily in the guise of lethargy, torpor, weariness, sluggishness, and lack of energy. Moreover, all these were thought to be typical symptoms of melancholia, which thus features some of the key symptoms of physical and mental exhaustion among its core indicators. Melancholia is a complicated disease entity, the exact definition and symptoms of which were subject to change through the centuries. For a long time, melancholia’s defining features were considered to be causeless sorrow and fear, but they were always accompanied by a range of other symptoms, among which the symptoms of physical and mental exhaustion feature prominently. Like neurasthenia, the diagnosis often encompasses a plethora of associated complaints, ranging from irritability, restlessness, mania, hallucinations, and paranoia to misanthropy and self-loathing.
3One of the most persistent myths surrounding the condition is the supposed link between a melancholic disposition and exceptionality, artistic inclinations, and “brain work.” It can be traced all the way back to Aristotle (or one of his followers), who wonders in
Problemata 30 (ca. 350
B.C.E.): “Why is it that all men who have become outstanding in philosophy, statesmanship, poetry or the arts are melancholic, and some to such an extent that they are infected by the diseases arising from black bile, as the story of Heracles among the heroes tells?”
4 Yet in the Middle Ages, melancholia was redefined in a theological context as acedia, with a particular focus on forms of lethargy, torpor, and lack of motivation, which were considered sinful diseases of the will and a sign of bad faith, as it was assumed to be within the power of the individual not to yield to these “demonic” temptations, which entailed contempt for the divine nature of God’s creation.
5 In the early modern period, melancholia was revalorized and once again associated with creativity, genius, and scholarship, and it was celebrated as the natural inclination of sensitive and emotional men in the age of Romanticism.
6 The nineteenth century saw the advent of biological medical models and psychiatric classificatory systems, and melancholia was explained in purely organic terms.
7 In the twentieth century, Sigmund Freud introduced the idea that melancholic self-loathing is a reaction to the loss of a love object and a form of narcissistic aggression turned masochistically against the self.
8 Currently, cognitive behavioral theorists understand some forms of depression, melancholia’s twentieth-century successor, as the result of distorted cognitive process and faulty reasoning.
9 Yet in spite of the eclectic diversity of explanatory models of melancholia, almost all accounts mention the physical and mental symptoms of states of exhaustion as either associated or primary symptoms.
Aristotle’s and Galen’s highly influential descriptions of the causes and symptoms of melancholia were to shape substantially all that followed. Galen explicitly theorizes exhaustion symptoms as belonging to the melancholic symptom cluster. The most important physician of the Roman era, trained in Platonic, Aristotelian, Stoic, and Epicurean systems of thought, Galen became court physician to the emperor Marcus Aurelius in Rome. He was a prolific writer and added his own empirical findings to past writings on medical subjects, in particular to Hippocrates’s teachings.
10 In
On the Affected Parts (composed after 192
C.E.), one of his most important treatises and originally written in Greek, Galen argues that a surplus of black bile triggers melancholia. He distinguishes between two types of melancholia. In the first kind, the entire blood supply of an individual becomes atrabilious, the melancholic humor thickening and slowing the blood, rendering the patient lethargic, slow, and prone to stupor.
11 (Interestingly, a general slowing of the patient’s movement and speech and the impairment of cognitive faculties are still considered behavioral signs of depression.)
12 Galen proposes that as a result of the denser texture of the black-bile-infected blood, it either does not reach the brain at all, as it travels more slowly and is often obstructed on the way, or else damages the brain’s functions by clogging up its pathways. The cure for this kind of melancholia entails bloodletting, so as to purge the excess of bilious fluids from the body and to reinvigorate the sluggish bloodstream.
The second kind of melancholia Galen describes in
On the Affected Parts originates in the stomach and can be caused by inflammation, indigestion, heartburn, and certain types of food. To fight these disturbances in the fluid economy, the body attempts to burn the excess of melancholic humors accumulating in the stomach. However, the ashes of the burned black bile rise to the brain in the form of a black vapor that subsequently clouds the sufferer’s judgment and feelings: “As some kind of sooty and smoke-like evaporation or some sort of heavy vapors are carried up from the stomach to the eyes, equally and for the same reason the symptoms of suffusion occur, when an atrabilious evaporation produces melancholic symptoms of the mind by ascending to the brain like a sooty substance or a smoky vapor.”
13Ostensibly figurative expressions still in use, such as “clouded judgment” and “black mood,” are thus rooted in what in ancient medical theory was actually thought to be the case: the assumption that the brain and its cognitive and affective functions were literally clouded and dulled by black vapors. (Interestingly, a strand in current depression research focuses on the role of negative attention and memory biases in the thought processes of the depressed, that is, the selective and often exclusive attention to and memory of negative information, which can be considered as forms of clouded judgment.) Galen emphasizes the literal link between darkness and melancholia elsewhere, too: not only is the color of the melancholic humor explicitly designated as black, but a certain type of person is more prone to becoming melancholic—that is, “lean persons with dark complexion, much hair and large veins.”
14 (Other twenty-first-century avenues of depression research involve the search for defective genes that predispose certain individuals to depression and for other definitive biological markers of the condition.) Moreover, the inherent qualities of black bile, coldness and dryness, are of course primarily associated with dead matter, organic life being defined by warmth and moisture.
In addition to more or less predetermined temperamental and physiognomic qualities, external circumstances and lifestyle choices can trigger melancholia. Like many other theorists writing on exhaustion syndromes, Galen is keenly interested in diet and compiles a long list of forbidden foods that can bring about atrabilious reactions. Among the potentially melancholia-inducing and energy-draining fare he counts
meat of goats and oxen, and still more of he-goats and bulls; even worse is the meat of assess and camels, since quite a few people eat these as well as the meat of foxes and dogs. Above all, consumptions of hares creates the same kind of blood, and more so the flesh of wild boars. [Spiral] snails produce atrabilious blood in a person who indulges in them, and so do all kinds of pickled meat of terrestrial animals, and of the beasts living in water, it is the tuna fish, the whale, the seal (phoke), dolphins, the dog shark and all the cetaceous species [related to the whale].
He also warns against the consumption of cabbage, sprouts prepared in brine, lentils, and “wheatbreads made from bran.”
15 Furthermore, he advises against the consumption of heavy and dark wine in large quantities, as well as aged cheeses. Other controllable lifestyle factors aggravating melancholic symptoms such as lethargy, weariness, and a dark mood can be lack of exercise and not enough sleep. (Again, physical exercise and a balanced diet are still thought to be important in the treatment of depression.)
While Galen emphasizes that every melancholic is unique, reacting differently to a surplus of black bile in the system, he agrees with Hippocrates’s basic definition of melancholia’s two key symptoms: “Fear or a depressive mood (dysthemia) which lasts for a long time render [patients] melancholic [that is, atrabilious].” All his melancholic patients, Galen writes, exhibit fear or despondency. One of them, for example, is afraid that “Atlas who supports the world will become tired and throw it away and he and all of us will be crushed and pushed together.”
16 This is a particularly telling fantasy of catastrophe, which betrays a timeless fear about the calamitous consequences of the waning of engagement, the inevitable decline of our physical and mental powers, and the inescapability of death. Galen’s melancholic patients also generally “find fault with life and hate people,” many tiring of life altogether and wishing to die.
Galen believes in the Hippocratic and Platonic idea of the division of the soul into three faculties: the rational, the spiritual, and the desiderative. Unlike Plato, he also believes that each of these faculties is seated in a particular organ: the rational part is thought to be located in the brain, the spiritual in the heart, and the desiderative in the liver.
17 Moreover, Galen proposes that the soul is embodied and that it is directly affected by bodily processes: “All of the best physicians and philosophers agree that the humors [
krâseis] and actually the whole constitution of the body change the activity of the soul.”
18 He does not conceive of the soul as an autonomous entity but repeatedly emphasizes that it is a “slave to the mixtures of the body” and that the body thus has the ability to deprive the soul of its energy:
19 “So one is bound to admit, even if one wishes to posit a spare substance for the soul, at least that it is a slave to the mixtures of the body: these have the power to separate it, to make it lose its wits, to destroy its memory and understanding, to make it more timid, lacking in confidence and energy, as happens in cases of melancholy.”
20The idea that physical processes essentially determine the soul, moods, and even specific behaviors starkly contrasts with later medical thinking, which frequently divides phenomena into those that pertain either to the mind or to the body, and which leaves little room for theorizing the complex interactions between the two entities. (There are parallels here to the arguments of researchers who believe in the purely biomedical origins of depression, that is, the idea that chemical processes in the brain, the “mixtures of the body,” are the exclusive determiners of our moods.) Galen draws on the authority of Plato to support further the idea that the bad humors of the body commonly cause diseases of the soul:
21When the humours of sharp and salty phlegm, or any other bitter and bilous humours, wander about the body without finding any path of exit, but are churned around and mix their spirit with the motions of the soul and are blended with it, they cause all kinds of diseases of the soul, great and small, few and many, in accordance with the three places of the soul to which they are brought, multiplying the kinds of ill-temper and low spirits, of bravery and cowardice, of forgetfulness and ignorance.
22Irritability, low mood, difficulty concentrating, and cognitive impairments are symptoms of exhaustion that frequently appear in other syndrome-clusters, too—for example, in later discussions of acedia, neurasthenia, and depression.
23According to Galen, melancholic exhaustion thus originates at a physical, almost proto-biochemical level and only in a second step proceeds to adversely affect the mind and the spirit by slowing or blocking the movement of the blood or by literally clouding the spirit. The causes of exhaustion symptoms such as weariness, lethargy, and torpor, as explained in the humoral framework, then, are essentially physiological in nature: it is the body that adversely affects the mind, and not, as twentieth-century psychosomatic theorists would argue, the other way around. Consequently, Galen also believes that doctors rather than philosophers should be charged with the improvement of the intellectual and moral qualities of the soul.
24Yet curiously, there appears to be no room in Galen’s model for the notion that purely mental processes can influence bodily reactions and result in physical symptoms—for example, that faulty reasoning and irrationally pessimistic interpretations of phenomena and experiences may become manifest in a physical lack of energy. Although Galen very briefly mentions “excessive worrying” and grief as potentially melancholia-enhancing phenomena, he never theorizes further how these psychological factors might actually interact with and affect the physical body.
While the humoral model of melancholia offers a theory of the ways in which the body affects the spirit, it centers on the idea that the mind and soul are pure and pristine, and that it is the body that acts as the corrupting force. But might not the mind also affect the body in a comparable way? Galen does not comment on this possibility. In contrast, many twenty-first-century biomedical researchers investigating the chemical makeup of depressed brains admit that they are not at all certain whether reduced serotonin levels are a consequence of depression or its cause. This matter is still essentially considered an unresolved chicken-and-egg question.
Both during and since the age of classical antiquity, the exact nature of the interrelation between the mind and the body has been the subject of ongoing speculation, and it is very far from having been resolved by modern science. In the Hellenistic period, the Greek writer Apollonius of Rhodes (b. ca. 295
B.C.E.) depicts in his epic poem
Argonautica a mind–body model that seems to be the exact opposite of Galen’s. While Galen grants the body absolute supremacy over the mind, Apollonius focuses instead on the potent influence of the mind over the body, showing how mental states affect physical energy levels. His epic is a hymn to positive thinking and the power of mind over matter, and his underlying psychomedical assumptions are much closer to twentieth- and twenty-first-century psychosomatic theories than to Galen’s one-way humoral model.
The
Argonautica, telling the myth of Jason and the Golden Fleece, is a classic quest narrative. Written in dactylic hexameters and modeled on the epics of Homer, this Hellenistic poem tells of the many challenges that Jason and the Argonauts have to overcome on their perilous sea voyage, the aim of which is to secure the fleece of a golden-haired winged ram from the faraway kingdom of Colchis. Jason is dispatched on the strenuous mission by the “chilling command of a wicked king,” Pelias, who was warned by an oracle to beware of a man wearing only one sandal.
25 This man turns out to be Jason, who arrives at court one day having lost one of his shoes. He obeys the king’s orders, puts together a crew, and heads for the waters of the Black Sea. They overcome numerous obstacles on their journey and, with the help of the Colchian princess Medea, who is well versed in the art of sorcery, successfully manage to complete a series of seemingly impossible challenges posed by her father, Aietes, king of Colchis, who does not want to give up the Golden Fleece. Aietes charges Jason with yoking two fire-spitting bulls, to plow the land and sow serpents’ teeth, from which spring a race of horrible earth-born warriors whom he has to defeat in battle. Although Jason succeeds in this task with the help of Medea’s tricks and potions, it becomes apparent that Aietes does not intend to honor his side of the deal, forcing the Argonauts to seize the Golden Fleece at night and to flee. They take Medea with them. Eventually, after much hardship and the loss of a number of their comrades, the Argonauts arrive safely back home in Iolkos in Greece.
Hellenistic culture saw the waning of Greece’s political and military powers and the rise of the Roman Empire. In keeping with the declinist cultural mood and a general focus on human weakness in the third century
B.C.E., Apollonius repeatedly shows Jason and his men being overcome by despair, grief, and hopelessness during their voyage.
26 Here, a pervasive atmosphere of cultural decline and political apathy, as well as strong instances of personal despair and hopelessness, form the basis of powerful examples of all-consuming exhaustion in its broader sociopolitical as well as individual-experiential manifestations. Jason’s helplessness contrasts starkly with the resourcefulness of his Homeric counterpart Odysseus: while the Homeric hero is described as
polymechanos (resourceful, with many resources), Apollonius calls Jason
amechanos (resourceless, without resources).
27 Jason, who is also neither of divine parentage nor blessed with any particular talents or skills, is thus from the outset (and by epic standards) characterized by a deficit, as a man who lacks the genealogical, emotional, and intellectual assets essential for the completion of his arduous mission. Jason is prone to despondency when faced with loss, death, and the many seemingly impossible challenges with which he has been tasked. Again and again, he sinks into the sand or falls to his knees, head in hands, overcome by exhaustion, and weeping bitterly over his fate.
The Argonautica is essentially a story of overcoming despondency, of battling with the demons of mental and physical exhaustion, and of not losing hope in the face of extreme adversity. Numerous scenes illustrate the ways in which hope and despair affect morale and the physical energy levels of the crew. From the very start, Jason’s moments of helpless despondency are legion: while the other Argonauts guzzle sweet wine and exchange entertaining stories at the beginning of their voyage, for example, “the son of Aison pondered upon everything helpless and absorbed, like a man in despair.” When the crew accidentally leaves Herakles and Polyphemos behind on the way to Colchis, “the son of Aison was so struck by helplessness that he could not speak in favour of any proposal, but sat gnawing at his heart because of the grim disaster which had occurred.” He frequently delivers pessimistic speeches to his men, bewailing the doomed nature of their mission and complaining about the burden of responsibility that is weighing on him:
I have erred; my wretched folly offers no remedy. When Pelias gave his instruction, I should have immediately refused this expedition outright, even if it meant a cruel death, torn apart limb from limb. As it is I am in constant terror and my burdens are unendurable; I loathe sailing in our ship over the chill paths of the sea, and I loathe our stops on dry land, for all around are our enemies. Ever since you all first assembled for my sake, I have endured a ceaseless round of painful nights and days, for I must give thought to every detail. You can speak lightly, as your worries are only for yourself. I have no anxiety at all for myself, but I must fear for this man and that, for you no less than for all our other companions, that I shall be unable to bring you back unharmed to Greece.
28Overwhelmed, anxious, paranoid, and unable to experience pleasure, he repeatedly wishes that he had chosen death instead of embarking on the quest for the Golden Fleece.
Jason reacts to the deaths of his comrades with prolonged periods of despair. Here, despair is manifest primarily as hopelessness, as a lack of faith in a better future resulting in apathy, both of which are symptoms of exhaustion. When a white-tusked boar kills one of the Argonauts, for example, the crew buries him without delay, “but then they sank down where they were on the shore in helpless despair, wrapped themselves in their cloaks, and lay still without thought for food or drink. Their hearts were depressed with sorrow, because all hope for a successful return seemed very far way.” The refusal of nourishment and a paralytic cessation of activity—which are also listed among the behavioral symptoms of twenty-first-century depression—are recurrent motifs in the epic. The Argonauts would have wallowed in their distress and delayed their journey indefinitely, had not the goddess Hera put boldness into the hearts of some of the men. They pass on her message by motivating their companions with hopeful speeches. Ankaios, for example, asks: “How can it be to our credit to ignore the challenge we have undertaken and to sit idle in a foreign land?” Immediately, Peleus’s heart “lifts in joy,” and he responds: “My poor friends, who do we grieve to no purpose? Nothing will come of it. We may suppose these men to have perished as their allotted fate decreed, but we have many steersmen among our number. Therefore let us not hold back from making the attempt: cast grief aside, and stir yourselves to your task!” Yet Jason’s view of the future continues to be somber. He predicts “disaster for us no less grim than what has befallen those who have died, if we neither reach the city of deadly Aietes nor return again through the rocks to the land of Hellas. Here a miserable fate will hide us from men’s view, without glory, growing old and useless.”
29When Aietes tasks the Argonauts with yoking the fiery bulls and fighting the earth-born warriors, the crew’s first reaction is once again to succumb to paralysis and inaction, a proleptic form of exhaustion: “To everyone the task seemed impossible; for a long time they sat in silence, unable to speak, and gazed at each other, depressed by the hopelessness of their wretched plight.” Whenever they find themselves stranded somewhere, they are ready to give up their mission. Trapped in a vaporous landscape near the stream Eridanos, for example, the men “desired neither food nor drink, nor did their minds have any thought of delights. The days they spent worn out and exhausted, weighed down by the foul smell which rose from the small branches of the Eridanos…. As they wept, their tears were carried on the waters like drops of oil.”
On their return journey, they find themselves cut off near the borders of Libya, in a particularly treacherous gulf with stagnant shallows. They can see only endless stretches of sand. Once again, they are seized by hopelessness when they disembark from their ship to explore the shore, for they “could see no source of fresh water, no path, no herdsmen’s yard far off in the distance; everything was in the grip of perfect calm.” In tears, the steersman declares to his distraught companions: “[W]e have lost all hope of continuing our voyage and of returning home safely.” Everyone agrees with the despairing man, and despondency spreads like wildfire among the crew:
All their hearts went cold and the colour drained from their cheeks. As when men roam through a city like lifeless ghosts, awaiting the destruction of war or plague or a terrible storm which swamps the vast lands where cattle work; without warning the cult statues sweat with blood and phantom groans are heard in the shrines, or in the middle of the day the sun draws darkness over the heavens and through the sky shine the bright stars: like this did the heroes then wander in aimless distress along the stretches of the shore. Soon the gloom of evening descended upon them. They threw their arms around each other in sorrowful embrace and wept as they took their leave; each would go off alone to collapse in the sand and perish. They separated in all directions, each to find a solitary resting-place. They covered their heads with their cloaks and lay all night long and into the morning, with no nourishment at all, waiting for a most pitiful death.
30All the members of the crew would have perished with their task uncompleted had not once again some benign goddesses with an interest in their fate taken pity on the men. They suggest to Jason a way out of his dilemma and whisper words of encouragement in his ear: “Rise up, and no longer groan in distress like this! Stir your comrades!” Immediately powerfully energized, Jason jumps up and shouts “like a lion which roars as it seeks its mate through the forest.” His companions, “their heads lowered in despair,” listen to his speech. He succeeds in rekindling their hope and convinces the crew to carry their boat for twelve whole days and nights through the sandy deserts of Libya. Although “suffering grievously under its weight,” they eventually reach Lake Triton, from which they continue their journey by boat.
31It is usually the gods who encourage the Argonauts to continue their quest and who urge them not to lose faith. Triton, the sea god, for example, tells them: “Go joyfully, and let no wearying grief come over you—your limbs burst with youth to meet the challenges ahead.” It is the divine agents who manage to reenergize the men when they have lost all hope—hopelessness being, of course, one of the primary mental and spiritual symptoms of extreme exhaustion.
While mental despair paralyzes the men and prevents them from taking action, there are also numerous references to physical exhaustion in the epic and to the extreme hardships of the journey. The Argonauts enter various different harbors “completely worn out by their efforts,” the relentless and vigorous plying of their oars rendering them “worn out and exhausted.” Exhaustion also figures frequently in the extended epic similes deployed by Apollonius, often to indicate the time of day. Time is measured by the degree of physical weariness of laborers, which is given a negative slant: “At the hour when a gardener or a ploughman, hungry for supper, is glad to return from the fields to his hut and, filthy with dust, squats down on his weary knees in the entrance to pour curses on his belly and stare at his worn hands, at that hour the heroes reached the land of Kios near Mount Arganthoneion and the mouth of the Kios.”
32Another simile also links physical weariness to time of day, but in a positive manner, referring to a good, satisfying kind of exhaustion that is temporary in nature and the result of physical exertion: “At the time when only the third part of the day which began at dawn is left, and exhausted labourers call for the swift arrival of the sweet hour at which they can release the oxen, then the field had been ploughed by the tireless ploughman, though it was four measures great, and the bulls were released from the plough.”
33Exhaustion, then, is one of the key themes in the Argonautica, its reach extending even to the level of figurative devices. Moreover, the epic provides a powerful model of the ways in which body and mind may interact. The examples cited demonstrate how hopelessness (an attitude or a state of mind) directly affects the crew’s ability to tackle the challenges they encounter. Following divine or human pep talks, as a result of which their outlook becomes more positive, they tap into hidden energy resources and develop superhuman strengths: the men are suddenly able to carry the Argo across the Libyan desert for twelve days and nights, while when their outlook was bleak they could do no more than lay apathetically in the sand, awaiting death. These episodes illustrate the powers that faith, confidence, and optimism can unleash and, conversely, the adverse effects on the body of negative states of mind.
Throughout the epic, Jason, as well as the Argonauts, vacillates between extreme states of hope and despair, in a manner that is characteristic of manic or bipolar depression. Either he leaps around joyfully, roaring like a lion, energizing his crew, or he sits in despair, head in hands, worn out by worry, ready to give up. While Jason’s and the Argonauts’ vacillations between exaltation and exhaustion are always direct reactions to external events (loss of comrades, grief, seemingly hopeless situations, being trapped in hostile lands), their attitudinal changes exemplify a more general cognitive and spiritual outlook toward human existence. When we find ourselves confronted with loss, or in hostile territory, or facing the other vicissitudes of life, Apollonius suggests, it is above all our state of mind that determines our potential to succeed or to perish. Hopelessness is a corrosive and highly infectious poison, while its opposites quite literally allow us to accomplish superhuman, seemingly impossible feats. In Apollonius, then, exhaustion is the result of a negative state of mind (often triggered by grief, loss, and the prospect or consequences of extreme physical challenges), but, crucially, it is a state that can be reversed through mental energizing. This view is, of course, congenial to the modern mind, being as it is an early version of the power of positive thinking.
34In addition to energizing us, ideas can also affect us in a negative way. In
Why Do People Get Ill?, Darian Leader and David Corfield explore unsettling psychosomatic research into the connection between mind and body, and the impact of psychological factors on what we tend to think of as purely physical illnesses. They analyze a large body of statistical and empirical evidence for mind–body dynamics that work exactly in the opposite manner from the model proposed by Galen.
35 Investigating phenomena such as the placebo effect;
36 the links between personality types and the statistical likelihood of developing certain kinds of illness; the power of metaphors and labels to shape illness experience and symptoms; the impact of loss, loneliness, and unhappiness on the body’s ability to fight off infectious diseases;
37 and the often significant timing of the onset of certain illnesses, they present compelling evidence for the ways in which the mind can affect the body.
Few people would deny the reality of the following mind–body exchange: vividly imagining an anxiety-inducing situation, such as having to speak in front of a large audience, or having to present someone with criticism of his or her actions, or having to tackle something of which we might be genuinely afraid—such as climbing a steep staircase without railings, flying, or catching a spider with our bare hands—produces physical reactions similar to those we would experience if we were actually in that situation. Our pulse may quicken, we might start sweating, and our breathing may become faster and shallower.
Yet the power of our thoughts and emotions over our body reaches much further than this; for example, it is a proven fact that stress and anxiety can weaken our immune system—in other words, that psychological factors can significantly affect immune function. Research has shown that our immune system is closely connected to the nervous and the endocrine system, and that we are much more susceptible to bacterial or viral illnesses when we are feeling low or overstretched.
38 Numerous experiments (based, for example, on blood samples taken from depressed and nondepressed subjects and medical students during and after exam periods) have demonstrated that in times of mental upheaval or pressure, the cytotoxicity of natural killer cells—the key agents of the immune system that identify and destroy threats—is significantly reduced.
39 Another experiment has shown that small wounds took 40 percent longer to heal in subjects tested during exam time compared with subjects tested during a vacation period.
40 If exam-time stress can so significantly affect wound healing, one can vividly imagine the effects of chronic exhaustion, depression, fear, anxiety, and stress on the body’s ability to heal and to defend itself against infectious diseases.
41 These and various other examples suggest that the connection between mind and body is much more complex than Galen imagined it to be in the second century
B.C.E., and perhaps closer to the model that Apollonius proposed.