Those early Greeks who believed that everything in the universe could be reduced to the same substance were called naturalists. Others believed that humans had special qualities which were different from the rest of the universe; they were called anti-naturalists. Still others attempted to use biological or physiological, rather than just physical, explanations of human activity. 2


1. What was the major belief of the Ionians? What are the monists?

2. What was the materialistic theory of Epicurus?

3. How is Heraclitus' theory different from that of others?

Let us return now to the influence of Greek philosophy upon the development of psychology. There are two groups of Greek philosophers. On the one hand are the early Greek philosophers of antiquity, and on the other hand are the later classical philosophers, primarily Plato and Aristotle.

According to Hamilton, Greek writing contains characteristics which parallel Greek thinking. They both tend to be plain, direct, and matter of fact. Greek writing and thinking are descriptive, not decorative or elaborative as is the English verse and prose. According to Hamilton, The English method is to fill the mind with beauty; the Greek method is to set the mind to work (Hamilton, 1948, p. 57). The Greeks saw beauty in common things; they admired facts. In contrast to the Greeks, also, were the Hebrews, who relied on emotion and feeling, which was partly facilitated by the repetition of ideas and word in their works.

The Greek thought of antiquity reflects two major trends regarding the nature of reality. One trend is represented by the naturalists, the other by the antinaturalists. These positions parallel modern day disputes between the scientific vs. the "third force" (humanistic) psychologies, to be discussed in Unit 9.


The early Greeks were intrigued by change as reflected in decay, instability, sentimentalism and the passing of youth. They also searched for the abiding, the lasting, and the stable, since nothing passes to nothing.

The early philosophers in Greece were the Ionians, who lived on the northwest of Caria. The chief interest among the Ionians was for the primary substance...(Burnet, 1892, p. 12).

Empedocles was the first to name the four basic elements, later made traditional by other philosophers. These elements were fire, air (really mist), earth, and water (Burnet, 1892). A sculptural conception of these Gods, representing these four elements, can be seen at the Metropolitan Museum of Art in New York City.

The naturalists believed in one reality, that both mind and man were a part of nature. They proposed a world view, according to the Ionians, of just one nature. This point of view of one reality is called monism. One after another of the Ionian philosophers proposed a single substance as the ultimate reality in the universe. .

Thales proposed that the source of matter was water, the most primitive of all three qualities (gas, liquid, solid). Water was ". . . The only substance that could exist in nature as solid, liquid, and vapor (Greer, 1964, p. xi)." Water was primitive because all things could be reduced to it. He was, therefore, the first monist (Durant, II). He had also noticed that magnets and static electricity both possessed the same animation, suggesting this as the source of all motion. His theory implies some common force, the interdependence of physical forces, or the conservation of force.

The other three Ionians each claimed one substance as the basic stuff of the universe -- Anaximander, the boundless; Anaximines, air; and Heraclitus, fire. Anaximander's boundless was an unlimited or an undefined. It was unlimited in quantity and undefined qualitatively. Man, he believed, was born of animals from another species, namely fish (Hale, 1970). Anaximines, on the other hand, believed that air was basic because air gets transformed into mist, then water, earth, and harder substances. As it becomes more rarefied, it turns into fire. He did not possess an atomic theory; air is continuous, not a composite of smaller elements. Air was the first principle. The pneuma was the breath, spirit, God -- and holds the world together (Durant, II).

The details of these early Ionian philosophers do not concern us here because their theories were simple and their influence upon western thought in general and psychology in particular was not very profound. It is important to recognize, however, that in this earliest stage of western thought, in the earliest attempts to formulate naturalistic rather than magical explanations, the systems were monistic.

Ionian monism was a belief in one basic unifying force or energy or substance in the universe. Monistic positions return again and again throughout the course of scientific and psychological thought. It is seen in Leibnitz's position, the assumption that there is one basic attribute in the universe, souls, though many different substances, monads. We see it in hypnotism, in early attempts to cure mental illness, where mental and physical forces are believed to be integrated. Later, in the nineteenth century, Helmholtz proposes the conservation of energy doctrine as a scientific attempt to explain all phenomena in biological and physical chemical terms. Freud, subsequently, reduces all psychic and neurotic energy to physical energy, to libido. The mystics and psychics also have maintained that mental forces can dominate physical forces.

Democritus (362 B.C.), the second of the naturalistic philosophers after the Ionians, was an atomic theorist. He believed the world was composed of atomic particles. This same notion recurs again in the epistemology of Hume, with the notion that impressions shower through the stream of experience -- in much the same fashion as Epicurus describes the physical atoms (Whitehead, 1933). Democritus believed in a soul that can influence matter. In summarizing Democritus, Durant states that "...soul or vital principle is part of the eternal energy in all things (Durant, II, pp. 147-48)." This idea of change and energy returns again under Bergson. "The conception of strife and struggle as determining all things reappears in Darwin, Spencer, and Nietzsche...(Durant, II, pl. 148)."

Epicurus (341 B. C.), the last of the naturalists, is a materialist and atomist who believed that the universe consisted of material bodies. But he was no substantive monist as regards the nature of reality. There is one basic substance, matter, but it has many different attributes. Since the universe is infinite, the number of elements in the universe is also infinite. There are different sensations because there are different sensible objects, resulting from different atoms. The number of different shapes is finite, though it is great; but the number of each shape is infinite (Geer, 1964).

There are three qualities of atoms -- size, mass, and shape. Each atom is different in size. Not every size is represented, however, or some would be large enough to be visible, which they are not. They are not infinitely divisible. Infinite divisibility would mean that some atoms are so small as to weaken their capacity even to exist. The atoms are in constant motion and constant collision producing the conditions whereby they reach our senses.

A thin film called idols is ejected from objects and creates sense perceptions and mental images which we see. These idols move at telegraphic speed; as soon as they leave the object they are replaced by new matter. This is what Titchener later called stimulus error -- error resulting when opinion or judgment adds something to the atoms.

The soul of man, no less than his body, is material also. In this regard, Epicurus anticipates the French school of materialism of the eighteenth century. It also anticipates contemporary scientific psychology, especially behaviorism. Epicurus argues that the soul must be material in order to act. That which is a void, which is incorporeal, cannot act, cannot bring about changes on the real world. Further, he makes a distinction between anima and animus. Anima is spirit or the whole body or unreason; animus is the mind or the breast, or reason (Geer, 1964). Later, we shall see how Jung uses these same terms but with different meanings.


All those who negate naturalistic explanations of human phenomena claim instead that the human condition has some special quality, are called the anti-naturalists. Durant refers to them as mystical. This group happens to include all the early Greek philosophers whose names begin with "P", with the exception of Protagoras. There is Pythagoras, Parmenides, Plato, Plotinus, and Paul. The only known one without a P is Heraclitus. The anti-naturalists maintain that humans are the center of the universe, the focus of attention by the gods. They have a unique quality in nature. This point of view is the background for Platonic philosophy.

Heraclitus (540-480 B.C.) was among the first of the antinaturalists, though in some respects the last of the naturalists. He was a naturalist because he proposed that there was one basic substance in the universe -- fire, the fourth of the four substances. He was also an anti-naturalist, however, because he seemed more interested in the appearances of things rather than in their basic reality. Reality is like a flame burning, which changes as you are watching it. (Durant, II, p. 144).

Heraclitus saw the universe as one of constant balance and harmonious change, in which things have the appearance of continuity but are actually going through the process of adding and subtracting, as a child changes gradually into an aged person over the years. So there is no basic reality, there is just the appearance of it. His famous analogy is how "you never step into the same river twice." It keeps changing as you watch it. Durant does not think, however, that Heraclitus was really that much interested in change, but rather in the one behind the many and varied in the universe. Heraclitus believed that the universe is a vast becoming. He was thus one of the first third force psychologists. In anticipation of Hegel, he rejected the idea of existence, per se. Nothing is; everything becomes. There was a great unity of opposites. Life and death are the same (Durant, II, p. 145). After Heraclitus, there was Parmenides, the Sophists, and Pythagoras, to which we now turn.

Parmenides (515 B.C.) was the father of materialism. Whatever is, is matter. He believed, therefore, that all matter had sensibility. This did not mean that all matter was sensed, but that matter had the capacity to be sensed if the senses were perfect enough. This close tie between human senses and material things led to a subjective point of view. This led the Sophists, later, to advocate that personal experience is a necessary avenue to human knowledge.

Parmenides denied that space or vacuum exists. His reason was that you cannot think of empty space. Only that of which we can think can exist. Since we cannot think of empty space, it does not exist.

And, if there is no space, then objects cannot move from one position to another. Alas, there can be no motion, no change, no decay. Notice later, how this issue divides theorists through the centuries. It is a central issue today between modern materialists and humanists, the former giving prominence to the general, one, material, and unchanging; the latter emphasizing individuality, plurality, and change.

But does not change exist? If so, what is it? Parmenides maintained that change and motion were only illusions. If our senses told us there is change, so much the worse for the senses! The what is, then, is just one thing. There is just one big, undifferentiated, uncreated, and indestructible thing in the universe -- a sphere, because that is the only thing which is equal in all directions, which is what you have if there is no space. If there is space, then you have space around what is, and some sides are longer than others. This one of Parmenides is like Leibnitz's monad, except that there is only one of them. Further, thought is a function of the limbs (Burnet, 1892, p. 297-98). That is because, as Anaxagoras maintained, one's hands determine one's intelligence.

Parmenides' position was a kind of monistic materialism. Whatever existed as matter could be sensed. There was no space because it could not be conceived; so there was only one thing. Later philosophers could not accept the fact that change and decay were only illusions. What of youth changing into old age, or trees growing tall and dying? Was life really just an illusion? Such a philosophical position could not long be maintained. There had to be some way to account for change. One needed to introduce the notion of space and therefore different kinds of materials (leading to Dualism or Pluralism in philosophy). Or else one had to advocate one substance which was not only matter. In the history of philosophy, either monism or materialism had to be discarded.

The Sophists returned to a position of making man central, claiming that experience leads to knowledge and knowledge, in turn, leads to self determination. Experience then is important because it leads to knowledge. It is the method of knowledge which is important, not the knowledge itself. This was the point made very strongly by Dewey, some nineteen hundred years later, when he advocated educational reform which would center on experiences of children rather than on the content of the subject matter.

Pythagoras (530 B.C.), preceding Parmenides and the Sophists, was the major philosopher who claimed that the ideal was the well adjusted, the well proportioned, and the most real. Pythagoras attempted to combine both reason and the irrational, to combine Apollo with Dionysius. The soul was a system of proportions. There were three parts to the soul -- instinct, feeling, and reason. The first two were shared by humans with animals; the last, reason, was man's alone (Hale, 1970). Pythagoras and philosophy became almost synonymous. He coined the term philosophia, meaning love of wisdom. The first principle was sought in form rather than matter, as Thales and the other Ionians maintained. It was this form which Plato eventually picked up and raised to a high level.

Biological Theorists

Other theorists emphasized a kind of personal, or human, or biological analysis of the universe. There are three biological theorists which stand out -- Anaxagoras, Empedocles, and Aristotle. We will discuss Aristotle together with Plato later and so now examine only Anaxagoras and Empedocles.

Anaxagoras (500-428 B.C.) was really the first philosopher, the first scientist to take residence in Athens [Burnet, 1892]. He came from Oionia and was probably brought over by Pericles, but the attacks which he made upon Pericles during the time of the Pelopenesian War brought Anaxagoras to his end. Athens was thoroughly an un-Athenian phenomenon, and so it was not the ideal location for Anaxagoras to settle down. As Durant suggests, Athens was so democratic, so much in fact, that mob rule prevailed; it was Athens where Socrates was murdered. Anaxagoras was the first dualist. There were small particles in the universe and a mind that acts on these particles. As the mind acts upon these particles, they are turned into objects which one sees. It is the nous by which all things are known. Nous imparts motion to the elements by a mechanical push-pull procedure. Nous organizes the world. [Esper, p. 90]. Nous becomes the cause of the motion of matter, external to matter and unique, whereas matter contains a part of everything. But he seems to use it when all other explanations fail, rather than to explain other phenomenon [Burnet, 1892]. Nous is mind, an immaterial power, lying outside the mass of the world, and sets the world in motion [Geer, 1964]. Anaxagoras' dualism also distinguished between the animate and the inanimate; the former, including plants, possessed nous. Nous is distinct from matter because it sets matter in motion [Burnet, 1892, p. 297]. Man is wiser than the other animals because he had hands, not because he had more nous [Burnet, 1892]. Anaxagoras' biological theory assumed that everything has a seed which explains that thing. A similar notion of growth potential, developed in more contemporary times, is the psychological theory of Maslow, May and Rogers and their theories of self actualization. Anaxagoras' point of view was consistent with the Zeitgeist of the times, in which many persons possessed considerable interest in physiological ideas [Burnet, 1892].

Anaxagoras held that perception was produced by opposites. An object can be sensed if it's background or surroundings are quite different. For example, green cannot be sensed when projected upon another green, if there is no contrast involved. Subsequent philosophers held that the same was true with ideas. The law of contrast in associationism held that something is remembered if it is in contrast to another or associated idea.

Empedocles (450 B.C.), a contemporary of Anaxagoras in the new classical Greece, also advanced a biological theory, and maintained that there are four substances plus something else. There is earth, air, fire, and water. And there are two forces, love and strife. Love brings things together which are unalike; it separates things which are alike. Strife brings like things together and separates unlike things.

Sensation is the recognition of like by like. The earth in us responds to the earthy part of other things; the air in us responds to the air part of other things, and so forth with fire and water. Thought is located in the blood because the blood has equal parts of all the elements in it, especially around the heart [Geer, 1964].

Sensation occurs when effluxes flow from the object to the eye and create vision. Effluxes are effusions, or outflows, which are continually given off by objects. The doctrine of effluxes was similar to the concept of electrified bodies, or magnets, wherein it was assumed that certain powers flowed out of the object and created changes in other objects. This appeared later in the popular concept of animal magnetism where electrical charges were coming off of baquets, metal or other objects and causing sensations, impressions and biological changes.

These then were the biological theorists who used biological or physiological explanations for sensation and knowledge rather than stopping merely with physical descriptions of the universe.



2000 Hebrews
1800-1150 Pre Homeric
1200 Trojan War
1100-850 Ionian migration; Dark Ages
1000 Homeric Age
840 Homer
814 Carthage founded
750 Hesiod

640 Thales
611 Anaximander
546 Anaximenes
535 Heraclitus
529 Pythagoras
522 Pindar
515 Parmenides
500-449 Persian Wars

497-500 Anaxagoras
484-424 Empedocles
475 Parmenides
470 Socrates
461 Pericles
431-404 Pelopensian Wars
427-347 Plato
384-322 Aristotle
336-323 Alexander
264 Punic War
260 Euclid

1 Before continuing to Module 3,
Complete Progress Checks 1 and 2.



Check those answers which are correct (one or more).

1. One reason why Thales believed that water was the source of all matter was because water:
a. was necessary for life
b. Was found on both land and water
c. Could be changed into liquid, gas, or solid
d. Was necessary for both plant and animal life

2. The Greek philosophers who were naturalists believed that:
a. One should do what comes naturally
b. Man was different from the rest of nature
c. Plants, animals, and humans were part of the same system
d. There were supernatural forces which controlled man

3. The Epicurean philosophy, that the world is made up of elements which have mass and size and shape is referred to as:
a. Materialism
b. Spiritualism
c. Monism
d. Dualism

4. Pythagoras believed that the ideal and the well proportioned was the most real. In this respect, he elevated to importance the notion of:
a. Form
b. Matter
c. Elements
d. Body

5. Dualistic theories, such as Anaxagoras', frequently include a belief in the difference between:
a. Plants and animals
b. Animals and humans
c. Animate and inanimate objects
d. Living and non-living substances

6. Heraclitus believed that:
a. you never step into the same river twice
b. things that appear to be constant are really continually changing
c. the world is basically constant
d. there is one substance underlying everything

Check your answers. 6 or more correct GO TO MODULE 3.
Less than 6 - Complete Exercises


1. There are two major kinds of Greek philosophers: Naturalists and _________________.

2. Those philosophers who believed that there was just one basic substance or reality in the universe were called _____________________.

3. Usually, Naturalists see man as just another part of nature, not as something special. This point of view is expressed today by the more "scientifically" oriented psychologists, e.g., the behaviorists who believe that man can be understood by studying other forms of nature, like animals. The anti-naturalists, on the other hand, held that humans are distinctly different from the rest of nature, that they are unique, special, and different. This point of view prevails today among the third force psychologists, e.g. the humanists, who hold that one cannot generalize from animal behavior to that of humans.

Aristotle, discussed in the next module, believed that man could be studied scientifically. He was,
therefore, more of a __________________. Plato, his teacher, had held that man had special qualities such as the capacity for reasoning, which was not shared by other animals. Plato was, therefore, more of a _________________.
4. Inanimate means _______________________.

5. Monism means _______________________.


4. Not living 5. Belief in only one ultimate reality

1. Anti-naturalists

2. Monists

3. Naturalist; anti-naturalist



1. Monists believed that there was/were (check answer below) basic substances in the universe.
a. One
b. Two
c. Three
d. Four

2. The belief that there was one basic unitary substance underlying the universe was held by:
a. The Ionians
b. The materialists
c. Epicurus
d. Pythagoras

3. The materialistic philosophy of Epicurus maintained that the universe was made up of an infinite number of elements and that sense perception results when:
a. These elements combined together
b. A thin film left the object for the eve
c. The eye saw the elements in a particular pattern
d. Coverings of objects called "idols" moved through the air

4. The anti-naturalists believed that:
a. Man was distinct from the rest of nature
b. The laws of nature did not apply equally to humans.
c. Nature was something which was basically evil
d. The universe was made up of individual spirits

5. As a dualist,Anaxagoras claimed that there:
a. Were two basic realities
b. Was only one reality
c. Was mind and matter
d. Were forces in the universe acting upon the mind.

6. Emphasis on physiological characteristics of behavior, such as in Behaviorism, have roots in
a. Heraclitus
b. Plato
c. Pythagoras
d. Epicurus

Check you answers. 4 or more correct go to Module 3.
Less than 4 - Instructor conference.

Contents Unit 2

Return to Module 2 text

Contents Unit 2

September 11, 1999