Ridling Zaine. Philosophy: Then and Now. A look back at 26 centuries of thought

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Ridling, Philosophy Then and Now: A Look Back at 26 Centuries of Thought

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philosophical categories as out of date. On the contrary side, Thomists

maintain that many of the notions advanced by Aristotle, not only in

metaphysics but also in physics, in psychology, and in ethics, are still really

valuable, quite independently of the evident fact that his “science” is now

altogether obsolete.

Atomism

In the broadest sense the term Atomism refers to any doctrine that

explains complex phenomena in terms of aggregates of fixed particles or

units. This philosophy has found its most successful application in natural

science: according to the atomistic view, the material universe is composed of

minute particles, which are considered to be relatively simple and immutable

and too small to be visible. The multiplicity of visible forms in nature, then, is

based upon differences in these particles and in their configurations; hence

any observable changes must be reduced to changes in these configurations.

The Basic Nature of Atomism

Atomism is in essence an analytical doctrine. It regards observable

forms in nature not as intrinsic wholes but as aggregates. In contrast to holistic

theories, which explain the parts in terms of qualities displayed by the whole,

Atomism explains the observable properties of the whole by those of its

components and of their configurations.

In order to understand the historical development of Atomism and,

especially, its relation to modern atomic theory, it is necessary to distinguish

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between Atomism in the strict sense and other forms of Atomism. Atomism in

the strict sense is characterized by three points: the atoms are absolutely

indivisible, qualitatively identical (i.e., distinct only in shape, size, and

motion), and combinable with each other only by juxtaposition. Other forms

of Atomism are less strict on these points.

Atomism is usually associated with a “realistic” and mechanistic view of

the world. It is realistic in that atoms are not considered as subjective

constructs of the mind employed for the sake of getting a better grip upon the

phenomena to be explained; instead, atoms exist in actual reality. By the same

token, the mechanistic view of things, which holds that all observable changes

can be reduced to changes of configuration, is not merely a matter of

employing a useful explanatory model; the mechanistic thesis holds, instead,

that all observable changes are caused by motions of the atoms. Finally, as an

analytic doctrine Atomism is opposed to organismic doctrines, which teach

that the nature of a whole cannot be discovered by dividing it into its

component parts and studying each part by itself.

Various Senses of Atomism

The term Atomism is derived from the Greek word atoma – ”things that

cannot be cut or divided.”

Two Basic Types of Atomism

The history of Atomism can be divided into two more or less distinct

periods, one philosophical, and the other scientific, with a transition period

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between them (from the 17th to the 19th century). This historical fact justifies

the distinction between philosophical and scientific Atomism.

Philosophical Atomism

In philosophical Atomism, which is as old as Greek philosophy,

attention was focused not on the detailed explanation of all kinds of concrete

phenomena but on some basic general aspects of these phenomena and on the

general lines according to which a rational explanation of these aspects was

possible. These basic aspects were the existence in nature of a manifold of

different forms and of continuous change. In what way could these features be

explained? Philosophical Atomism offered a general answer to that question.

It did not, however, strictly confine itself to the general problem of explaining

the possibility of change and multiplicity – not even in ancient Greek

Atomism, for in Greek thought philosophy and science still formed a unity.

Consequently, Atomists also tried to give more detailed explanations of

concrete phenomena, such as evaporation, though these explanations were

meant more to endorse the general doctrine of Atomism than to establish a

physical theory in the modern sense of the word. Such a theory was not yet

possible, because a physical theory must be based upon indirect or direct

information about the concrete properties of the atoms involved, and such

information was not then available.

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Modern Atomic Theory

With the development of a scientific atomic theory, the general

philosophical problems gradually disappear into the background. All attention

is focused on the explanation of concrete phenomena. The properties of the

atoms are determined in direct relationship with the phenomena to be

explained. For this reason the chemical atomic theory of the 19th century

supposes that each identified chemical element has its own specific atoms and

that each chemical compound has its own molecules (fixed combinations of

atoms). What particles act as unchanged and undivided units depends upon

what kind of process is involved. Some phenomena, such as evaporation, are

explained by a process in which the molecules remain unchanged and

identical. In chemical reactions, however, the molecules lose their identity.

Their structures are broken up, and the composing atoms, while retaining their

own identity, are rearranged into new molecules. With nuclear reactions a new

level is reached, on which the atoms themselves are no longer considered as

indivisible: more elementary particles than the atoms appear in the

explanations of nuclear reactions.

Extensions to Other Fields

Whereas classical Atomism spoke mainly of material atoms (i.e., of

particles of matter), the success of the atomic doctrine encouraged the

extension of the general principles of Atomism to other phenomena, more or

less removed from the original field of application. Rather plausible, for

example, was the extension of Atomism to the phenomena of electricity.

There were reasons to suppose the existence of an elementary charge of

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electricity associated with an elementary material particle, the electron (19th

century). A second fruitful extension concerned energetic processes (20th

century). Some experimental data suggested the hypothesis that energy can

exist only in amounts that are whole multiples of an elementary quantity of

energy. Extensions of the idea of an atomic structure to amounts of gravitation

and even to time have been attempted but have not been sufficiently

confirmed.

More removed from the original field of application of Atomism is a

theory known as Logical Atomism (developed by the eminent philosopher and

logician Bertrand Russell and by the philosopher of language Ludwig

Wittgenstein), which supposes that a perfect isomorphism exists between an

“atom” of language (i.e., an atomic proposition) and an atomic fact; i.e., that

for each atomic fact there is a corresponding atomic proposition. An atomic

proposition is one that asserts that a certain thing has a certain quality; e.g.,

“this is red.” An atomic fact is the simplest kind of fact and consists in the

possession of a quality by some individual thing.

Another application of Atomism (albeit in a moot sense) lies in the

monadology of the philosopher-scientist G.W. Leibniz. According to Leibniz

the atoms of Democritus, who provides the paradigm case of ancient Greek

Atomism, were not true unities; possessing size and shape, they still were

divisible in principle. The ultimate constituents of things must, therefore, be

points, said Leibniz – not mathematical but metaphysical points; i.e., points of

real existence. They are indeed a kind of soul, which he came to call

“monads.”

In psychology, Atomism is a doctrine about perception. It holds that

what man perceives is a mosaic of atomic sensations, each independent and

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unconnected with any other sensation. According to the early modern

Empiricist David Hume and the pre-World War I father of experimental

psychology Wilhelm Wundt, the fact that man nevertheless experiences an

ordered whole formed from the unordered “atoms” of perception is caused by

the mind’s capacity to combine them by “association.”

Diverse Philosophical Characterizations of Atomism

The Intrinsic Nature of the Atoms

In 1927 the Belgian astronomer Georges Lemaître formulated the

hypothesis that the present high degree of differentiation of matter in space

and the complexity of forms displayed by the various astronomical objects

must have resulted from a violent explosion and subsequent dispersal of an

originally highly compressed homogeneous material, a kind of “primitive

atom,” containing all of the matter that exists. From the philosophical

viewpoint this hypothesis is interesting. By its attempt to reduce the manifold

to unity it recalls the beginning of Greek philosophy, which was also inspired

by a thesis of the unity of being, propounded by the Eleatic Parmenides. Even

apart from their respective contexts, there is, of course, a great difference

between Lemaître’s and Parmenides’ conceptions of the unity of being, for the

latter combined the thesis of the unity of being with that of the immutability of

being.

Although it would be wrong to classify Parmenides among the Atomists,

it is nonetheless appropriate that in an introduction to the diverse forms of

Atomism, his conception of reality as just one being should be mentioned.

Parmenides’ thesis is not only historically but also logically the cornerstone of

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atomistic thought. Any atomic theory can be interpreted as an attempt to

reconcile the thesis of the unity and immutability of being with the fact that

the senses observe multiplicity and change. The different ways in which the

unity and immutability are understood characterize the different forms of

Atomism.

Atoms as Lumpish Corpuscles

As corpuscles (minute particles), atoms can either be endowed with

intrinsic qualities or be inherently qualityless.

The most striking basic differences in the material world, which lead to a

first classification of substances in nature, are those between solids, liquids,

gases, and fire. These differences are an observed datum that must be

accounted for by every scientific theory of nature. It is, therefore, only natural

that one of the first attempts to explain the phenomena of nature was based

upon these differences and proclaimed that there are four qualitatively

different primitive constituents of everything, namely, the four elements:

earth, water, air, and fire (Empedocles, 5th century BCE) – a theory that

dominated physics and chemistry until the 17th century.

Although the theory of the four elements is not necessarily an atomistic

theory, it obviously lends itself to interpretation in atomistic terms, namely,

when the elements are conceived as smallest parts that are immutable. In this

case, all observable changes are reduced to the separation and commingling of

the primitive elementary substances. Thus Parmenides’ thesis that being is

immutable is maintained, whereas the absolute unity of being is abandoned.

Yet, the fact that the infinite variety of forms and changes in nature is reduced

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to just one type of process between only four elementary kinds of atoms

shows its affinity with the thesis of the unity of all being.

Notwithstanding the great disparity between the theory of the four

elements and modern chemistry, it is clear that modern chemistry with its

approximately 100 qualitatively different atoms falls into the same class of

atomic theories as that of Empedocles. There are differences, of course, but

these will be deferred for later discussion.

More removed from the original thesis of Parmenides was the theory of

his contemporary Anaxagoras of Clazomenae, which assumed as many

qualitatively different “atoms” as there are different qualitied substances in

nature. Inasmuch as these atoms, which Anaxagoras called “seeds,” were

eternal and incorruptible, this theory still contains an idea borrowed from

Parmenides. A special feature of Anaxagoras’ theory was that every substance

contains all possible kinds of seeds and is named after the kind of seed that

predominates in it. Since the substance contains also other kinds of seed, it

can change into something else by the separation of its seeds.

Another interesting form of Atomism with inherently qualitied atoms,

also based on the doctrine of the four elements, was proposed by Plato. On

mathematical grounds he determined the exact forms that the smallest parts of

the elements must have. Fire has the form of a tetrahedron, air of an

octahedron, water of an icosahedron, and earth of a cube. Inasmuch as he

characterized the atoms of the four elements by different mathematical forms,

Plato’s conception can be considered as a transition between the qualitative

and quantitative types of Atomism.

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The most significant system of Atomism in ancient philosophy was that

of Democritus (5th century BCE). Democritus agreed with Parmenides on the

impossibility of qualitative change but did not agree with him on that of

quantitative change. This type of change, he maintained, is subject to

mathematical reasoning and therefore possible. By the same token,

Democritus also denied the qualitative multiplicity of visible forms but

accepted a multiplicity based on purely quantitative differences. In order to

reduce the observable qualitative differences to quantitative differences,

Democritus postulated the existence of invisible atoms, characterized only by

quantitative properties: size, shape, and motion. Observed qualitative changes

are based upon changes in the combination of the atoms, which themselves

remain intrinsically unchanged. Thus Democritus arrived at a position that

was defined above as Atomism in the strict sense. In order to make the motion

of atoms possible, this Atomism had to accept the existence of the void

(empty space) as a real entity in which the atoms could move and rearrange

themselves. By accepting the void and by admitting a plurality of beings, even

an infinite number of them, Democritus seemed to abandon – even more than

Empedocles did – the unity of being. Nevertheless, there are sound reasons to

maintain that, in spite of this doctrine of the void, Democritus’ theory

remained close to Parmenides’ thesis of the unity of being. For Democritus’

atoms were conceived in such a way that almost no differences can be

assigned to them. First of all, there are no qualitative differences; the atoms

differ only in shape and size. Secondly, the latter difference is characterized

by continuity; there are no privileged shapes and no privileged sizes. All

shapes and sizes exist, but they could be placed in a row in such a manner that

there would be no observable difference between successive shapes and sizes.

Thus not even the differences in shape and size seem to offer any ground

explaining why atoms should be different. By accepting an infinite number of

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atoms, Democritus retained as much as possible the principle that being is

one. With respect to the acceptance of the void, it must be stressed that the

void in the eyes of Democritus is more nonbeing than being. Thus even this

acceptance does not seriously contradict the unity of being.

Atoms as Sheer Extension

Democritus had declared quantitative differences to be intelligible,

because they were subject to mathematical reasoning. Precisely this

relationship between quantitative differences and mathematics made it

impossible for Descartes (17th century) to think along the atomistic lines of

Democritus. If the only thing that is clearly understandable in matter is

mathematical proportions, then matter and spatial extension are the same – a

conclusion that Descartes did not hesitate to draw. Consequently, he rejected

not only the idea of indivisible atoms but also that of the void. In his eyes the

concept “void” is a contradiction in terms. Where there is space, there is by

definition extension and, therefore, matter.

Yet, however strange it may seem in view of his identification of matter

with extension, Descartes offered nonetheless a fully developed theory of

smallest particles. To the questions that arise immediately as to how these

particles are separated and distinct from each other, Descartes answered that a

body or a piece of matter is all of that which moves together. In the beginning

of the world all matter was divided into particles of equal size. These particles

were in constant motion and filled all of space. As, however, there was no

empty space for moving particles to move into, they could only move by

taking the places vacated by other particles that, however, were themselves in