by Morton Hunt
Protagoras
Alcmaeon’s ideas were borne around the far-flung Greek cities by travelers; soon, philosophers in many places were devising their own explanations of how perception takes place, and a number of them asserted that it was the basis of all knowledge. But some saw the troubling implications of this view. Protagoras (485–411), best known of the Sophists (a term that then meant not fallacious reasoners but “teachers of wisdom”), unsettled his contemporaries and pupils by pointing out that, since perception was the only source of knowledge, there could be no absolute truth. His famous apothegm, “Man is the measure of all things,” meant, he explained, that any given thing is to me what it appears to me to be, and, if it appears different to you, is what it seems to you to be. Each perception is true—for each perceiver. Philosophers were willing to debate the point, but politicians considered it subversive. When Protagoras, visiting Athens, tactlessly applied his theory to religion, saying there was no way for him to know whether the gods exist or not, the outraged Assembly banished him and burned his writings. He fled and drowned at sea en route to Sicily.
Democritus
Others carried on that line of inquiry, devising explanations of how perception takes place and maintaining that, since knowledge is based on perception, all truths are relative and subjective. The most sophisticated of such musings were those of Democritus (460–362) of Abdera, Thrace, the most learned man of his time. Vastly amused by the follies of humankind, he was known as the “laughing philosopher.” His main claim to fame, actually, derives not from his psychological reflections but from his extraordinary guess that all matter is composed of invisible particles (atoms) of different shapes linked together in different combinations, a conclusion he came to, without any experimental evidence, by sheer reasoning. Unlike Alcmaeon’s air channels, this theory would eventually be proven absolutely correct.
From his theory of atoms Democritus derived an explanation of perception. Every object gives off or imprints on the atoms of the air images of itself, which travel through the air, reach the eye of the beholder, and there interact with its atoms. The product of that interaction passes to the mind and, in turn, interacts with its atoms.3 He thus anticipated, albeit in largely incorrect detail, today’s theory of vision, which holds that photons of light, emanating from an object, travel to the eye, enter it, and stimulate the endings of the optic nerves, which send messages to the brain, where they act on the brain’s neurons.
All knowledge, according to Democritus, results from the interaction of the transmitted images with the mind. Like Protagoras, he concluded that this means we have no way of knowing whether our perceptions correctly represent what is outside or whether anyone else’s perception is identical with our own. As he put it, “We know nothing for certain, but only the changes produced in our body by the forces that impinge upon it.”4 That issue would vex philosophers and psychologists from then until now, driving many of them to devise elaborate theories in the effort to escape the solipsistic trap and to affirm that there is some way to know what is really true about the world.
Hippocrates
When the early philosopher-psychologists concluded that thought occurs in the mind, it was only natural that they would also wonder why our thoughts are sometimes clear and sometimes muddled, and why most of us are mentally healthy but others are mentally ill.
Unlike their ancestors, who had believed mental dysfunction to be the work of gods or demons, they sought naturalistic answers. The most widely accepted of these was that of Hippocrates (460–377), the Father of Medicine. The son of a physician, he was born on the Greek island of Cos off the coast of what is today Turkey. He studied and practiced there, treating many of the invalids and tourists who came for the island’s hot springs and achieving such renown that far-off rulers sought him out. In 430 Athens sent for him when a plague was ravaging the city; observing that blacksmiths seemed immune to it, he ordered fires built in all public squares and, legend says, brought the disease under control. Only a handful of the seventy-odd tracts bearing his name were actually written by him, but the rest, the work of his followers, embody his ideas, which are a mixture of the sound and the absurd. For instance, he stressed diet and exercise rather than drugs, but for many diseases recommended fasting on the grounds that the more we nourish unhealthy bodies, the more we injure them.
His greatest contribution was to divorce medicine from religion and superstition. He maintained that all diseases, rather than being the work of the gods, have natural causes. In this spirit, he taught that most of the physical and mental ills of his patients had a biochemical basis (though the term “biochemical” would have meant nothing to him).
He based this explanation of health and illness on the prevailing theory of matter. Philosophers had held that the primordial stuff of the world was water, fire, air, and so on, but Empedocles concocted a more intellectually satisfying theory, which dominated Greek and later thinking. All things, he said, are made up of four “elements”—earth, air, fire, and water—held together in varying proportions by a force he called “love” or kept asunder by its opposite, “strife.”5 Though the specifics were wholly wrong, many centuries later scientists would find that his core concept—that all matter is composed of elemental substances alone or in combination—was quite right.
Hippocrates borrowed Empedocles’ four-element theory and applied it to the body. Good health, he said, is the result of a proper balance of the four bodily fluids, or “humors,” which correspond to the four elements—blood corresponding to fire, phlegm to water, black bile to earth, and yellow bile to air. For the next two thousand years physicians would attribute many illnesses to humoral imbalances that they would try to cure by draining off an excess of a humor (as in bloodletting) or by administering medicines supplying one that was lacking. The harm this caused over the centuries, particularly through bloodletting, is incalculable.
Hippocrates used the same theory to explain mental health and illness. If the four humors were in proper balance, consciousness and thought would function well, but if any humor was either in excess or short supply, mental illness of one kind or another would result. As he wrote:
Men ought to know that from the brain, and the brain only, arise our pleasures, joys, laughter, and jests, as well as our sorrows, pains, grief, and tears… These things that we suffer all come from the brain when it is not healthy but becomes abnormally hot, cold, moist, or dry… Madness comes from its moistness. When the brain is abnormally moist, of necessity it moves, and when it moves, neither sight nor hearing is still, but we see or hear now one thing and now another, and the tongue speaks in accordance with the things seen and heard on any occasion. But when the brain is still, a man is intelligent.
The corruption of the brain is caused not only by phlegm but by bile. You may distinguish them thus: those who are mad through phlegm are quiet, and neither shout nor make a disturbance; those maddened through bile are noisy, evil-doing, and restless…The patient suffers from causeless distress and anguish when the brain is chilled and contracted contrary to custom; these effects are caused by phlegm, and it is these very effects that cause loss of memory.6
Later, followers of Hippocrates extended his humoral theory to account for differences in temperament. Galen, in the second century A.D., said that a phlegmatic person suffers from an excess of phlegm, a choleric one from an excess of yellow bile, a melancholic one from an excess of black bile, and a sanguine one from an excess of blood. That doctrine persisted in Western psychology until the eighteenth century and remains embedded in our daily speech—we call people “phlegmatic,” “bilious,” and so on—if not our psychology.
Although the humoral theory of personality and of mental illness now seems as benighted as the belief that the earth is the center of the universe, its premise—that there is a biological basis to, or at least a biological component in, personality traits and mental health or illness—has lately been confirmed beyond all question. A vast amount of recent re
search by cognitive neuroscientists has identified many of the substances produced by brain cells and shown how these enable thought processes to take place, and myriad other studies have shown that foreign substances such as drugs or toxins distort or interfere with those processes. Hippocrates was close to the mark after all.
One can only marvel at the psychological musings of Hippocrates and the pre-Socratic psychophilosophers. Quite without laboratories, methodology, or empirical evidence—indeed, without anything but open minds and intense curiosity—they recognized and enunciated a number of the salient issues and devised certain of the theories that have remained central in psychology from their time to our own.
The “Midwife of Thought”: Socrates
We now come upon a man unlike the shadowy figures we just met, a real and vivid person whose appearance, personal habits, and thoughts are thoroughly documented: Socrates (469–399), the leading philosopher of his time and the proponent of a theory of knowledge that directly contradicted perception-based theory. We know a good deal about him as a person because two of his pupils—Plato and the historian-soldier Xenophon—set down detailed recollections of him. Unfortunately, Socrates himself wrote nothing, and his ideas come to us chiefly through Plato’s dialogues, where much of what he says is probably Plato’s own thinking put in Socrates’ mouth for dramatic reasons. Nonetheless, Socrates’ contributions to psychology are clear.
He lived during the first half of Athens’ era of greatness (the span from its defeat of the Persians at Salamis in 480 to the death of Alexander in 323), when philosophy and the arts flourished as never before. The son of a sculptor and a midwife, he was fascinated by what he learned of philosophy in his youth from Protagoras, Zeno of Elea, and others. He early decided to make it his life work, but, unlike the Sophists, he took no fees for his teaching; he would talk to anyone who wanted to discuss ideas with him. He occasionally worked as a stonecutter and carver of statues but preferred the luxury of thought and discourse to the comforts money could buy. Content to be poor, he wore one simple shabby robe all year and went barefoot; once, looking about in the marketplace, he exclaimed with pleasure, “How many things there are that I do not want!”
Not that he was an ascetic; he liked good company, sometimes went to banquets given by the wealthy, and freely confessed to feeling a “flame” within him when he peered inside a youth’s garment. Uncommonly homely, with a considerable paunch, a bald head, broad snub nose, and thick lips, he looked like a satyr, his friend Alcibiades told him. Unlike a satyr, however, he was a model of moderation and self-control; he seldom drank wine, remained sober when he did, and was chaste even when in love. The beautiful and amoral Alcibiades, slipping into Socrates’ bed one night to seduce him, was astonished to be treated as if by a father. “I thought I had been disgraced,” he later said, according to Plato’s Symposium, “and yet I admired the way this man was made, and his temperance and courage.”
Socrates kept himself in good physical condition; he fought bravely during the Peloponnesian War, where his ability to withstand cold and hunger amazed his fellow soldiers. After long years of instructing his pupils, he was tried and condemned for his teachings, which Athenian democrats said corrupted youth. The real problem was that he was contemptuous of their democracy and numbered many aristocrats, their political foes, among his followers. He accepted the verdict with equanimity and refused the opportunity to escape, preferring to die with dignity.
Although the Delphic Oracle once declared Socrates the wisest man in the world, he disputed that pronouncement; it was his style to claim that he knew nothing and was wiser than others only in knowing that he knew nothing. He claimed to be a “midwife of thought,” one who merely helped others give birth to their ideas. This, of course, was a pose; in reality he had a number of firmly held opinions about certain philosophic matters. But unlike many of his contemporaries, he was uninterested in cosmology, physics, or perception; as he says in Plato’s Apology, “I have nothing to do with physical speculations.” His concern, rather, was with ethics. His goal was to help others lead the virtuous life, which, he said, comes about through knowledge, since no man sins wittingly.
To help his students attain knowledge, Socrates relied not on lectures but on a wholly different educational method. He asked his students questions that seemingly led them step by step to discover the truth for themselves. This technique, known as dialectic, was first used by Zeno, from whom he may have learned it, but it was Socrates who developed and popularized it. In doing so, he promulgated a theory of knowledge that would be the major alternative to perception-based theories from then on.
According to that theory, knowledge is recollection; we learn not from experience but from reasoning, which leads us to discover knowledge that exists within us (“to educate” comes from the Latin meaning “to lead out”). Sometimes Socrates asks for definitions and then leads his partner into contradictions until the definition is reshaped. Sometimes he asks for or offers examples, from which his partner finally makes a generalization. Sometimes he leads him, step by step, to a conclusion that contradicts one he had previously stated, or to a conclusion he had not known was implicit in his beliefs.
Socrates cites geometry as the ideal model of this process. One starts with self-evident axioms and, by hypothesis and deduction, discovers other truths in what one already knew. In the Meno dialogue he questions a slave boy about geometrical problems, and the boy’s answers supposedly show that he must all along have known the conclusions to which Socrates leads him; he was unaware that he knew them until he recalled them through dialectical reasoning. Similarly, in many another dialogue Socrates, without presenting an argument or offering answers, asks a friend or pupil questions that lead him, inference by inference, to the discovery of some truth about ethics, politics, or epistemology—in each case, knowledge he supposedly had but was unaware of.
We who live in an era of empirical science know that Socratic dialectic, though it can expose fallacies or contradictions in belief systems or lead to new conclusions in such formal systems as mathematics, cannot discover new facts. Until Anton van Leeuwenhoek (1632–1723 A.D.) first saw red corpuscles and bacteria under his lens, no Socratic teacher could have led his pupils or himself to “remember” that such things existed; until astronomers saw evidence of the “red shift” in distant galaxies, no philosopher could, through logical searching, have discovered that he already knew the universe to be expanding at a measurable rate.
Yet Socrates’ teachings greatly affected the development of psychology. His view that knowledge exists within us and needs only to be recovered through correct reasoning became part of the psychological theories of persons as diverse as Plato, Saint Thomas Aquinas, Kant, and even, in a sense, those present-day psychologists who maintain that personality and behavior are largely determined by genetics, linguists who say that our minds come equipped with language-comprehending structures, and parapsychologists who believe that each of us has lived before and can be “regressed” to recall our previous lives.
The notion that we have lived before is related to Socrates’ other major impact on psychology. He held that the existence of innate knowledge, revealed by the dialectic method of instruction, proves that we possess an immortal soul, an entity that can exist apart from the brain and body. With this, the vague mythical notions of soul that had long existed in Greek and related cultures assumed a new significance and specificity. Soul is mind but is separable from the body; mind does not cease to be at death.
On this ground would be built Platonic and, later, Christian dualism: the division of the world into mind and matter, reality and appearance, ideas and objects, reason and sense perception, the first half of each pair regarded not only as more real than but as morally superior to the second. Although these distinctions may seem chiefly philosophic and religious, they would pervade and affect humankind’s search for self-understanding throughout the centuries.
The Idealist: Plato
He w
as named Aristocles, but the world knows him as Plato—in Greek, platon, or “broad”—the nickname he was given as a young wrestler because of the width of his shoulders. He was born in Athens in 427 to well-to-do aristocratic parents, and in his youth was an accomplished student, a handsome charmer of men and women, and a would-be poet. At twenty, about to submit a poetic drama in a competition, he listened to Socrates speaking in a public place, after which he burned his poetry and became the philosopher’s pupil. Perhaps it was the gamelike quality of Socrates’ dialectic that captivated the former wrestler; perhaps the subtlety of Socrates’ ideas entranced the serious student; perhaps the quiet and serenity of Socrates’ philosophy appealed to the son of ancient lineage in that era of political upheaval and betrayal, war and defeat, revolution and terror.
Plato studied with Socrates for eight years. He was a dedicated student and something of a sobersides; one ancient author says that he was never seen to laugh out loud. A few scraps of love poetry attributed to him exist, some of them addressed to men, some to women, all of doubtful authenticity, and there is almost no gossip about his love life and no evidence that he ever married. Still, from the wealth of detail in his dialogues, it is evident that he was an active participant in Athenian social life and a keen observer of behavior and the human condition.
In 404, an oligarchic political faction that included some of his own aristocratic relatives urged him to enter public life under its auspices. The young Plato wisely held back, waiting to see what the group’s policy would be, and was repelled by the violence and terror it used as its tools of government. But when democratic forces regained power, he was even more repelled by their trial and conviction of his revered teacher, whom he calls, in the Apology, “the wisest, the justest, and best of all men I have ever known.” After Socrates’ death, in 399, Plato fled Athens, wandered around the Mediterranean meeting and studying with other philosophers, returned to Athens to fight for his city, then again went wandering and studying.
