by Morton Hunt
But unlike Plato he had the hunger for empirical data and the love of painstaking observation that have characterized science ever since. Despite the high value he placed on deductive reasoning and formal logic, he continually stressed the importance of inductive reasoning— the derivation of generalizations from observed cases or examples, a fundamental part of scientific method and a way of arriving at knowledge exactly contrary to that advocated by Plato.
For far from regarding sense perceptions as illusory and untrustworthy, Aristotle considered them the essential raw material of knowledge.18Extraordinary for one who had studied with Plato, he had, says one Aristotle scholar, “an intense interest in the concrete facts”;19 he regarded the direct observation of real things, except in abstract domains such as mathematics, to be the foundation of understanding. In De Generatione Animalium, for instance, after admitting that he does not know how bees procreate, he says:
The facts have not yet been sufficiently established. If ever they are, then credit must be given to observation rather than to theories, and to theories only insofar as they are confirmed by the observed facts.20
Like earlier philosophers, he sought to understand how perception takes place, but having no way to gather hard data on the matter— testing and experimentation were unknown, the dissection of human bodies impermissible—he relied on metaphysical explanations. He theorized that we do not perceive objects as such but their qualities, such as whiteness and roundness, which are nonmaterial “forms” that inhere in matter. When we see them, they are re-created within the eye, and the sensations they arouse are transmitted through the blood vessels to the mind—which, he thought, must be in the heart, since people often recover from injuries to the head while wounds to the heart are invariably fatal. (The brain’s function, he thought, was to cool the blood when it became overly warm.) He also discussed the possible existence of an interior sense, the “common” sense, by means of which we recognize that various sensations arriving from different sense organs—say, white and round, warm and soft—come from a single object (in this case, a ball of wool).
If we ignore these absurdities, Aristotle’s explanation of how perceptions become knowledge is commonsensical and convincing, and complementary to the perception-based epistemologies of Protagoras and Democritus. Our minds, Aristotle says, recognize the similarities in a series of objects—this is the essence of inductive reasoning—and from those common traits form a “universal,” a word or concept signifying not an actual thing but a sort of thing or a general principle; this is the route to higher levels of knowledge and wisdom. Reason or intellect thus acts upon sense data; it is an active, organizing force.
Having spent so many years examining biological specimens, Aristotle was of no mind to regard the objects of perception as mere illusions, or to rank generalized concepts as more real than the individual things they summarize. Where Plato said that abstract ideas exist eternally, apart from material things, and are more real than they, his realistic pupil said they were only attributes that could be “predicated” of specific subjects. Though he never totally abandoned the metaphysical trappings of Greek thought, he came close to saying that universals have no existence except in the thinking mind. He thus synthesized the two main streams of Greek thinking about knowledge: the extreme emphasis on sense perception of Protagoras and Democritus and the extreme rationalism of Socrates and Plato.
About the relation of mind to body, at times he is hopelessly opaque, at other times crystal clear. The opacity concerns the nature of “soul,” which, waxing metaphysical, he calls the “form” of the body—not its shape but its “essence,” its individuality, or perhaps its capacity to live. This muddy concept was to roil the waters of psychology for many centuries.
On the other hand, his comments about that part of the soul where thinking takes place are lucid and sensible. “Certain writers,” he says in De Anima, “have happily called the soul the place of ideas, but this description applies not to the soul as a whole but merely to the power of thought.”21 Most of the time he calls the part of the soul where thinking takes place the psyche, although sometimes he uses that term to mean the entire soul; despite the inconsistency, he is consistent in saying that the thinking part of the soul is a place where ideas are formed, not a place in which they exist before the soul inhabits the body.
Nor is soul, or psyche, an entity that can exist apart from the body. “It is clear,” he says, “that the soul is not separable from the body, and the same holds good of particular parts of the soul.”22 He rejects the Platonic doctrine of the imprisoned soul whose highest goal is to escape from the bonds of matter; in contrast to Plato’s dualism, his system is essentially monistic. (But this is his mature view. Because his views changed during his lifetime, Christian theologians would be able to find ample material in his early writings to justify their dualism.)
Once he has these matters out of the way, Aristotle gets to his real interest: how the mind uses both deduction and induction to arrive at knowledge. His description constitutes, according to Robert Watson, “the first functional view of mental processes…[For him] psyche is a process; psyche is what psyche does.”23 Psyche isn’t an immaterial essence, nor is it the heart or blood (nor, even if he had located psyche in the brain, would it have been the brain); it is the steps taken in thinking—the functionalist concept that today underlies cognitive science, information theory, and artificial intelligence. No wonder those who know Aristotle’s psychology stand in awe of him.
His description of thought processes sounds as if he based it on laboratory findings. He had none, of course, but being so diligent a collector of biological specimens, he may well have done something analogous, that is, scrutinized his own experiences and those of others, treating them as the specimens on which he based his generalizations.
The most important of these is that the thinking mind, whether functioning deductively or inductively, uses sense perceptions or remembered perceptions to arrive at general truths. Sensation brings us perceptions of the world, memory permits us to store those perceptions, imagination enables us to re-create from memory mental images corresponding to perceptions, and from accumulated images we derive general ideas. Radically differing with his mentor, Plato, Aristotle did not believe that the soul is born with knowledge. According to Daniel Robinson, he believed that
human beings have a cognitive capacity by which the (perceptual) registration of externals leads to their storage in memory, this giving rise to experience, and from this—“or from the whole universal that has come to rest in the soul”—a veritable principle of understanding arises (Post. Anal. 100 1–10).24*
It is an extraordinary vision of what scientific psychology would document twenty-three centuries later.
Because he was a creature of his time, some of his comments about memory seem nonsensical now; he said, for instance, that we remember things best when the memory is moist, worst when it is dry, and that very young persons have poor memories because the surface (of the wax tablet–like memory) changes rapidly through growth. But many of his observations were perceptive and close to the mark. For example, the more often an experience is repeated, the better it is remembered. Another: Events experienced only once but under the influence of strong emotion may be better remembered than others experienced many times. And another: We recall things from memory by relying on various kinds of connections among our ideas—similarity, contrast, and contiguity. To find a lost memory, for instance, we call to mind something we believe or know will lead us to the memory we are after.
Whenever we try to recollect something, we experience certain of the antecedent movements [i.e., memories] until finally we come to the one after which customarily comes the one we seek. This is why we hunt up the series, having started in thought either from a present intuition or some other, and from something either similar or contrary to what we seek, or else from that which is contiguous to it.25
Though this is hardly deathless prose, David
J. Murray, a historian of psychology, writes, “The last sentence here is possibly the most influential written in the history of psychology, for it enunciates the belief that we are moved by association from one concept to the next.”26 That belief would, from the seventeenth century on, be the foundation of a major theory of learning and a principal way of accounting for human development and behavior.
In De Anima and other works, Aristotle dealt briefly with or touched tangentially on a number of other psychological matters. Though none warrants our close attention, the range and perceptiveness of these comments are remarkable. Among other things, he offered a theory of motivation in terms of pleasure and pain, touched on the drives producing various kinds of behavior (courage, friendship, temperance, and others), and sketched the theory of catharsis (the vicarious purgation of pity and fear) to explain why we feel rewarded by seeing tragedies in the theater.
We may chuckle at some of his wilder guesses, like a good meal making us sleepy because digestion causes gases and body heat to collect around the heart, where they interfere with the psyche. But, writes Robert Watson, the “study of Aristotle is rewarded by a feeling of wonder at the modernity of much of what he says about psychological matters…He was, of course, wrong in many of his ‘facts’ and he omitted important topics, but his overall framework of growing, sensing, remembering, desiring, reacting, and thinking, with but a few changes, bear[s] more than a resemblance to modern psychology.”27
* Throughout this chapter, the dates given are B.C. unless otherwise noted.
*All emphases in quotations are those of the quoted writers.
TWO
The
Scholars
The Long Sleep
If it is difficult to account for the sudden appearance and vigor of psychology in Greece, it is almost as difficult to explain the dormancy that overtook it after Aristotle, a sleep that would last two thousand years. Not until the seventeenth century would psychological questions again fascinate and galvanize thoughtful men as they had during the brief flowering of Greek culture.
Yet “dormancy” and “sleep” are misleading; they imply a lack of awareness that was far from being the case. Throughout the twilight of Greek greatness, the Pax Romana, the transformation of society by Christianity, the disintegration of the Roman Empire, the emergence of feudalism in its ruins, and the renewal of learning during the Renaissance, psychology was neither moribund nor forgotten. During those many centuries and metamorphoses of society, some intellectuals continued to ask the questions posed by the Greek philosophers and to formulate answers to them. But they did so as scholarly commentators, reworking what had already been done, rather than as explorers and innovators; not one of them had a major new idea that significantly advanced psychological knowledge.
Perhaps by the end of Aristotle’s life psychology had developed almost as far as speculation and reflection could take it. After his time, those who were interested in psychological phenomena continued to rely on that approach, but the science could not progress without observation, measurement, sampling, testing, experimentation, and other empirical procedures.
There is, however, another and larger explanation of the long sleep: none of the social and religious systems that dominated Western civilization for those two millennia inspired men to explore the psychological unknown. For different reasons, Hellenistic society, Roman society, and Christianity motivated those who thought about psychological matters to do no more than pore over the work of their predecessors and revise it to fit their own belief systems.
Yet what these scholars, compilers, and redacters did deserves our attention for two reasons. For one, in the history of every science there are long periods when its practitioners labor at minor modifications of accepted theory in the effort to make it fit unruly facts. During such periods the science, like a pupa in a cocoon, undergoes changes preparing it to emerge new and altered. What takes place during the dormant phase may be less dramatic than the emergence of the metamorphosed creature but is no less essential to the advance of knowledge.
For another, during the latter half of the dormancy of psychology, Christian scholars who winnowed and modified Greek theories of psychology added to them, on theological grounds, certain nonscientific hypotheses about human nature that live on in popular thinking to this day. A look at how and when these hypotheses were developed will help us understand such contemporary debates as whether consciousness can exist in a disembodied mind (as in, say, out-of-body or back-from-death experiences) or whether it is a concatenation of physical and chemical events occurring in a living brain.
The Commentators
Theophrastus
When Aristotle left Athens in 323 because of political turmoil, he named his longtime friend and colleague Theophrastus head of the Lyceum; he also later bequeathed to him his library and the original manuscripts of all his works. Clearly, Aristotle had the highest regard for him.
Theophrastus (372–287) was indeed a distinguished teacher and scholar. He ran the Lyceum efficiently for many years, and was so eloquent a lecturer that two thousand people at a time would come to hear him. And he was phenomenally industrious, completing during his lifetime 227—some say 400—works on religion, politics, education, rhetoric, mathematics, astronomy, logic, biology, and other subjects, including psychology.
Yet Aristotle, for all his good judgment, could not foresee that almost no one would remember or read any of Theophrastus’s works except the most trifling of them, the Characters. This was a series of brief satirical portraits of such archetypes as the Flatterer, the Garrulous Man, and the Stupid Man—the original exemplars of a genre of literature that has been popular ever since. The sketches are psychological writing in the broad sense that they report behavioral phenomena, but they add nothing to our understanding of the origins or development of traits or patterns of personality.
Theophrastus’s other works have been deservedly forgotten. In them he restated, compiled, commented on, and criticized, but added little to, what others had said before him. This is especially true of On the Senses, his treatise on psychology; he says many sensible things, but they are no more than evaluations of, or faultfinding with, the work of his predecessors. This is typical:
[Democritus] attributes perception, pleasure, and thought to respiration and to the mingling of air with blood. But many animals are either bloodless or do not breathe at all. And were it necessary for the breath to penetrate the entire body and not merely special parts—[a notion]…he introduces for the sake of a part of his theory—there would be nothing to prevent all parts of the body from remembering and thinking. But reason does not have its seat in all our members—in our legs and feet, for instance—but in specific parts by means of which, at the proper age, we exercise memory and thought.*1
The Hellenists
Theophrastus’s writing about psychology is typical of what one finds in the works of post-Aristotelian philosophers of the Hellenistic period, the two centuries following Alexander’s death and the dividing up of his empire by three of his generals. Such commentary broke no new ground, but it did begin the compilation of the defects of Greek psychological thinking that two millennia later would drive a few inquisitive men to devise new hypotheses and, for the first time, test them scientifically.
What was true of psychology in the Hellenistic era was true of much other intellectual activity. The compilation and criticism of the ideas of thinkers of the preceding centuries flourished as libraries grew, particularly in Alexandria, where Ptolemy I, King of Egypt, established the greatest library of antiquity. Only in certain sciences did new ideas appear: geometry, which Euclid greatly expanded; hydrostatics, in which Archimedes made the epochal discovery that an object submerged in a fluid loses as much weight as the fluid it displaces; and geography, which Eratosthenes greatly furthered by calculating the circumference of the earth and coming respectably close to the correct figure. (He did so by measuring the shadow of an obelisk at noon in Alexandria on the day
when the noontime sun shone straight down a deep well in Aswan, and, by geometrical means, determining the curvature of earth that could produce the disparity in the shadows.)
These and other sciences in which progress was made had become partly emancipated from philosophy; their practitioners, ignoring metaphysical issues, sought knowledge not through philosophic speculation but empirically. (Mathematics is nonempirical, but Euclid’s approach to it was at least free of the mysticism of the Pythagorean geometers.) Psychology, meanwhile, in which no empirical methodology had been conceived of, remained a branch of philosophy.
Which was in decline. The wars that raged intermittently throughout Macedonia and the Near East, and the gradual decay of the social order in the former Greek city-states, engendered weariness and pessimism. Instead of searching for ultimate truths, philosophers sought solace; they distracted themselves with astrology, Near Eastern religions, and mystical adaptations of Platonism, and they narrowed philosophy to systems of ethics that would teach them how to live wisely in troubled times.
In this milieu, psychology no longer greatly interested philosophers. The Platonists and Aristotelians merely ruminated on and refined the hypotheses of their masters. The adherents of three popular new schools, the Epicureans, Skeptics, and Stoics, limited their psychological discussions largely to Democritus’s epistemology (the theory that we know only what the senses tell us, from which we extract ideas and meaning through the use of reason), patching up any flaws they noticed and adding a few notions necessitated by their ethics.
