LEIBNITZ (1646-1716)

Leibnitz, a German scientist and founder of the Calculus, became the father of activity psychology and today's third force psychology because he emphasized the mind side of Descartes' dualism and proposed a theory of monads, or centers of activity. His theory of psychophysical parallelism became a model for one solution to the mind body problem. 1


1. What were Leibnitz' scientific contributions?
2. How does Leibnitz differ from Locke?
3. How is psychophysical parallelism different from interactionism?
4. How does monadology parallel or antedate third force psychology today?
5. What is the relationship between Leibnitz' calculus and his theory of development?

During the seventeenth century, Descartes established the importance of both matter and mind. After him, two divergent schools of thought emerged, one emphasizing the importance of mind, the other the importance of matter. To the first is associated the name of Leibnitz, leader of what became known as mentalistic, faculty, activity psychology, a primarily German point of view that mind, present at birth, imposed order and structure on matter. In opposition to this point of view was Locke, founder of British empiricism who claimed that all was basically matter, that mind was simply the passive reflection of a material world.

We turn first to Leibnitz who emphasized the mind side of Descartes' dualism and raised that to primary importance. In the next module we will examine the point of view of Locke.

In his own day, Leibnitz was a well known favorite of the court, just as Descartes was before him in France and Locke, after him, in England. But Leibnitz spent more years than did the others as an employee of political figures in Europe. For a time he was an assistant to the Archbishop of Mainz, a little German town along the Rhine River which Louis XIV hoped to add to his already burgeoning French empire. Leibnitz, asked to help thwart the potential threat of Louis, came up with an ingenious solution. Distract Louis by thoughts of snatching Egypt from the Turks, towards whom Louis was already hostile, and the Rhine provinces might be saved. Louis, however, surprised everyone by turning his attention to the acquisition of new lands in Holland and the Spanish Netherlands.

Under contract to the Elector of Brunswick, Leibnitz spent a good number of years writing a family history of the Hanover family. Many eventS distracted Leibnitz from his work. Near the end of his life the history was still unfinished and his relationship with the Elector became strained. The Elector was selected to succeed Charles II to the throne of England and to become the William of William and Mary. Leibnitz fully expected to accompany the new monarchs to their adopted country, but his lagging work on the family history frustrated this opportunity.


As one of the greatest leaders in the world of science, Leibnitz was elected the first president of the Berlin Academy of Science which he organized in 1700. He had hoped that Berlin would become (1) the depository for information from other scientific societies, (2) a museum to house the scientific treasures of the world, and (3) the universal center of science. In his pursuit of scientific activities, Leibnitz corresponded with and made visits to members of the Royal Society of London. He traveled to England, met with Newton and other scientific leaders, and was granted honorary membership in the Royal Society. His conversations with Peter the Great led to the founding of the St. Petersburg Academy of Sciences. Among his own scientific contributions was the infinitesimal calculus. Although Newton invented the calculus, Leibnitz was the first to publish his calculus and the notations he invented have become standard usage today.

Leibnitz' scientific activities commenced only after he visited Huygens, the great French scientist, in Paris and Boyle in London. His visit to Paris in 1672 was just one year before Huygens published his Horologium Oscillatorium, a work which Singer (1959) claims is perhaps the greatest scientific work next to the Principia. The work was a "mathematical analysis of the principles of the pendulum clock." Durant claims that Leibnitz' analogy of the clocks in the concept of preestablished harmony was adapted from the Flemish philosopher Geulincy, but it is possible that Leibnitz' early interest in the coordinated movements of the universe was a direct result from his association with Huygens, who was his mentor.

The English scientist Robert Boyle was the other great person who influenced Leibnitz (Singer, 1959, p. 309) and with whom Leibnitz visited the year after his meeting with Huygens. Boyle was instrumental in founding the Royal Society and had written The Sceptical Chymist (1661), in which he appealed for a chemistry based on scientific methods rather than upon an empirical art. He argued that chemistry should be an inductive science rather than a technology. He was not interested in a technology which produced simply practical results like metals on the one hand or medicinal ministrations to the sick on the other hand. Chemistry should be, argued Boyle, a "theoretical explanation" rather than a "practical exploitation (Wolf, 1959, v. 1, p. 337)."


Leibnitz had attempted, against the increasing empiricism of Locke, to save for philosophy and religion the concept of the human mind as did McDougall over Watson and Rogers over Skinner, the old controversy of Plato and Aristotle. Locke, following Aristotle, was claiming that the mind was a tabula rasa, a blank tablet, and was at birth an impressionable but impressionless mind. Leibnitz quickly retorted that the mind was neither blank nor vacuous. When Locke said there is nothing in the mind, Leibnitz replied, "Nothing is in the mind that has not been in the senses, except the mind itself (Durant, v. 8, pp. 668-669)."

In arguing with Locke, Leibnitz said "The question between us is whether the soul in itself is entirely empty. . . according to Aristotle . . . or. . . contains the principles of several notions and doctrines, which the external objects only awaken on occasions, as I believe with Plato (Lewes, 1888, p. 542)." The mind, he thought, was actively systematizing the scattered sensations. The mind "transforms" sensations into mental patterns, as the digestive organs process food into assimilable elements. The transformation processes of the mind depend upon certain "innate" characteristics. These innate traits are not innate "ideas" or contents of the mind but rather categories of thinking or ways of structuring sensation. Some examples of these mental components were substance, unity, identity, reason, etc.

Alchemy was of popular interest at the time and coincided with Leibnitz' notion of the mind as a "transforming" mechanism. Leibnitz played an active though modest role as secretary for the newly developed Rosicrusians, a society of alchemists, physicians, and clergymen which was organized in 1654. Alchemy was the "science of transforming the raw materials of nature into the finished products useful to humanity (Mason, Mason, 1953, p. 181)," a definition used by Parcelsus, the leading alchemist in the seventeenth century. Physicians pondered the physiological transformations in the body. Food was transformed into natural spirits. Air and blood, mixed in the heart, produced vital spirits which were in turn transformed into the animal spirits of the brain. These animal spirits in turn produced movements in the body (Jaffe, 1949, p. 12). This system had come down from Galen of Pergamon.

These alchemists, explaining health and illness in chemical terms, later became pharmacists who studied how physical symptoms became transformed by drugs and chemicals.

Theologians were also interested in transformation, of which there are many examples found in the theology and the ritual of the church. The wine and bread of the sacrament, when blessed by the priest and elevated during the mass, became transformed into the body and blood of Jesus Christ. A heathen or sinner, converted during a religious service, became transformed into a believer. This modification of physical or spiritual phenomena was the cornerstone principle for religious belief and practice from the middle ages to the present. Much of religion and later most of education attempted to transform persons or institutions into some more desirable form.

Psychophysical Parallelism

Although mind was the more important reality, it was not the only one. Leibnitz, following Descartes and Plato, maintained that there were two realities, mind and matter. His dualism differed from Descartes' in one important respect -- how the mind and matter were related. While Descartes maintained that mind interacted with matter, where one could influence or change the other, Leibnitz, on the other hand, held that mind and matter were parallel, and that each were independent and incapable of influencing each other. Leibnitz borrowed from the Flemish philosopher, Geulinex, the notion of a "preestablished harmony," a correlation between mind and matter originally established by God. No one side of the dualism could influence the other, since God was the only source of power. The two realities, like two clocks, were wound up and set going, each telling the same time with different mechanisms and different hands. Or, like two railroad tracks going to the same place, they existed side by side, parallel. This brand of dualism was called "psychophysical parallelism."


Dynamic. The concept of "will" and the exertion of will was the most characteristic trait following the Thirty Years War (Myers, 1952). Science pivoted on the notion of force, especially force from a distance, a concept elaborated on by Kepler and Newton. In theology, this was expressed in the dualism of will and grace. In architecture, the concepts of force and mass were dynamic ideas replacing the characteristic Renaissance concepts of weight and support. Leibnitz made force the basis for reality. Descartes defined force as mass times velocity. Leibnitz, using Galileo's work, suggested that force was mass times velocity squared, which is close to the current formula of one half mass times velocity squared. Leibnitz made force the basic substance after Galileo and Newton emphasized the idea that motion was made of infinitely small impulses. Substance, then, is force.

Leibnitz, copying Bruno, called the basic microscopic units of the universe "monads," the foundation for his theory of "monadology." Presumably, Leibnitz had peered through the recently invented microscope, and was fascinated with the prospect of an infinitely divisible world. These microscopic monads were centers of force; they were unique; and they were unitary and completely independent but varying in degrees of clarity. Leibnitz believed that the nature of the universe was mental or spiritual, not material, and so monads were psychic, not materialistic, and moved in the direction of greater clarity (mind or God) from confusion (substance).

How did Leibnitz view science? He advocated what is now popularly known as the unity of science movement. As a mathematician, Leibnitz saw variations in quantity not quality. He claimed that nature makes no leaps, a principle which he called the"law of continuity." In passing from one position to another, there is an infinity of positions in between. There is in the universe one grand continuous gradation -- from man to animals, from animals to plants, and from plants to inanimate objects. This is an all encompassing conception of the universe, rather than a conception of diverse, individual, qualitatively different elements. Here in the middle of the seventeenth century is the anticipation of evolutionary theory. The basic ideas of Darwin are laid out in simple format. Ironically, however, the descendents of Leibnitzian thought, the act psychologists, the Gestaltists, the humanists, the tender-minded, have all rejected those studies which suggest individual quantitative differences among persons, and argue against analogies between human and animal behavior because man is qualitatively different.

But consistent with third force psychology is Leibnitz' notion that nature adheres not only to a continuous pattern of development but also to one with a progressive direction. "Progress will never come to an end," says Leibnitz (Durant, v. I, p. 677). And so, the world moves onward and upward. This world is, of course, the best of all possible world -- until the next one.

A great optimist, Leibnitz earned for himself the title of "the best of all possible worlds man (Durant, v. 8, p. 675)," when he wrote, in 1710, the book Theodice. In the next century, Voltaire's satires of Candide and Pangloss were based upon the person of Leibnitz.

Leibnitz was obsessed by the concept of "unity." He was determined to create unity, to preserve unity, and to find unity not only in animals and in man but in the political and spiritual domains as well. The disunity among Catholics and Protestants was at that time seriously threatening European unity. Leibnitz, seeking some measure of accommodation, was criticized for what appeared to be an "indifference." Unsuccesssful in his attempts to bring Catholic and Protestant forces together, he turned his attention to a reconciliation among the Protestants, especially between the Lutheran and Calvinist branches. These groups proved equally obstinate, and his high expectations for religious unification were finally dashed.

Leibnitz also sought the unification of political realms. Germany, divided into multitudinous units, longed for national unity. Although Leibnitz believed that it is more prudent to convert the leader than to educate the masses, he was not successful in educating the emperor of the empire.

Leibnitz traveled extensively on both political and scientific missions. In later years, turning more to himself, he shunned those contacts with others which interfered with the privacy of his own work. His isolation was so complete that when death finally came, only one person his secretary, appeared at his funeral. This is a sad commentary on the life of a man who contributed to the advancement of science as well as to the protection of religion from science.

To summarize Leibnitz' position and find a clue to the man, one might look to the books he valued most.1 According to Durant, Leibnitz believed that there were "only two kinds of books with any value: those reporting scientific demonstrations or experiments, and those containing history, politics, or geography (Durant, v. 1, p. 667)."

It is apparent that Leibnitz formed the tradition for activity psychology, a system reflected in writings of the German philosophers Kant and Herbart, and the Gestalt psychologists Koffka and Kohler. The third force psychologists, a tradition begun by Maslow and continued by May, Rogers, and others, reflect the same active mind and dynamic systems as represented by Leibnitz.

The next unit examines the system of Locke, representing the beginning of what became known as British Empricism, a system in opposition to that of the dynamic schools and emphasizing the body side of Descartes' dualism.


Check those answers which are correct (one or more) or fill in the blank spaces.

1. Leibnitz was:
a. German
b. English
c. Dutch
d . French

2. The process by which raw materials are changed into some humanly desirable product is referred to as _________________________________.

3. For Leibnitz, mind was:
a. The only reality
b. One of the realities along with matter
c. Part of dualism
d. Parallel to the body

4. Leibnitz believed that there was (were)
a. One reality
b. Two realities
c. Psychophysical interactionism
d. Psychophysical parallelism

5. The most important concept of Leibnitz was that of:
a. Force
b. Monism
c. Unity
d. Materialism

6. The prevailing point of view of Leibnitz was his belief in:
a. Discrete changes in the universe
b. Continuous changes in the universe
c. Step like modifications in growth
d. Gradual differences between animals and men

7. The question of motion in the universe was directly related to the concept of:
a. force
b. unity
c. dualism
d. parallelism

8. In regards to the nature of the mind, Leibnitz differed radically from:
a. Descartes
b. Locke
c. Newton
d. Hobbes

7 or more correct GO TO MODULE 4.

LESS THAN 7 - Complete Exercises.


1. Leibnitz was reared and lived most of his life in what country? __________________________.

2. As an extension of Descartes' dualism, Leibnitz was the philosopher who emphasized primarily the __________________ side of his dualism

3. It was undoubtedly Leibnitz's interest in ____________________ which contributed to a philosophy emphasizing the interrelationships among diverse fields.

4. For Leibnitz, the mind was:
a. Static
b. A "tabula rasa"
c. Dynamic
d. Actively changing sensations

5. Leibnitz differed from Descartes over a conception of dualism. Leibnitz believed that mind and body, established by God, did not cause the other. This point of view is referred to as psychophysical ____________________________.

6. The basic units in the universe, centers of force rather than definable elements, were called, by Leibnitz, __________________________________.

7. The English scientist, Bacon, influenced Leibnitz and advocated ______________________ rather than deductive approaches to science.

8. The theorists today most sympathetic with Leibnitz are the _________________________.


7. Inductive
3. History
1. Germany
5. Parallelism
8. Gestaltists
4. C, D
6. Monads
2. Mind



1. Leibnitz was a(n):
a. Historian
b. Mathematician
c. Alchemist
d. Psychologist

2. Transformation refers to the fact that:
a. One element might change into a different element
b. One person might be able to change an element into another element
c. Mental processes might be changed into physical phenomenon
d. Physical phenomenon might change into mental phenomenon

3. The persons most interested in transformation were:
a. Chemists
b. Alchemists
c. Theologians
d. Physicians

4. Monads were:
a. Centers of force
b. Unique
c. Discrete atomic particles
d. Unitary

5. Leibnitz sought unity both within nature and among divergent political structures. His philosophical position reflecting his theory of reality he referred to as ______________________________________.

6. Leibnitz was one of the greatest:
a. Historians
b. Scientists
c. Theologians
d. Physicians

7. In regard to the relation between the mind and body problem, Leibnitz disagreed primarily with:
a. Descartes
b. Locke
c. Bacon
d. Newton

8. Psychophysical parallelism:
a. maintained that there was only one reality
b. held that matter influenced mind and vise versa
c. was endorsed by Descartes
d. held that mind and matter were correlated.

1. (p. 21). Leibnitzian philosophy frequently defies comprehension. Leibnitz may have attempted too many things and tried to integrate too much. Professor Randall, Woodbridge Professor of Columbia University, makes a heartening statement when he says that it is most difficult to provide "any unified picture of Leibnitz's thought... The historian may feel less sure of Leibnitz than of any other major figure in the philosophical record...his thought contains such a rich variety of incompatibles... an account of Leibnitz is impossible (1965, p. 5)." Randall further states that "... while Leibnitz has a wealth of intellectual imagination... he has quite literally very little sense... Much that he says is profound, and much is nonsense; he cannot tell the difference (Randall, 1965, p. 10)."

Go on to Module 4

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