THE ATOMISTS
The founder of the Atomist philosophy was Leucippus. Practically
nothing is known of his life. The date of his birth, the date of his
death, and his place of residence, are alike unknown, but it is
believed that he was a contemporary of Empedocles and Anaxagoras.
Democritus was a citizen of Abdera in Thrace. He was a man of the
widest learning, as learning was understood in his day. A passion for
knowledge and the possession of adequate means for the purpose,
determined him to undertake extensive travels in order to acquire the
wisdom and knowledge of other nations. He travelled largely in Egypt,
also probably in Babylonia. The date of his death is unknown, but he
certainly lived to a great age, estimated at from ninety to one
hundred years. Exactly what were the respective contributions of
Leucippus and Democritus to the Atomist philosophy, is also a matter
of doubt. But it is believed that all the essentials of this
philosophy were the work of Leucippus, and that Democritus applied and
extended them, worked out details, and made the theory famous.
Now we saw that the philosophy of Empedocles was based upon an attempt
to reconcile the doctrine of Parmenides with the doctrine of
Heracleitus. The {87} fundamental thought of Empedocles was that there
is no absolute becoming in the strict sense, no passage of Being into
not-being or not-being into Being. Yet the objects of the senses do,
in some way, arise and pass away, and the only method by which this is
capable of explanation is to suppose that objects, as whole objects,
come to be and cease to be, but that the material particles of which
they are composed are eternally existent. But the detailed development
which Empedocles gave to this principle was by no means satisfactory.
In the first place, if we hold that all objects are composed of parts,
and that all becoming is due to the mixing and unmixing of
pre-existent matter, we must have a theory of particles. And we do
hear vaguely of physical particles in the doctrine of Empedocles, but
no definition is given of their nature, and no clear conception is
formed of their character. Secondly, the moving forces of Empedocles,
Love and Hate, are fanciful and mythological. Lastly, though there are
in Empedocles traces of the doctrine that the qualities of things
depend on the position and arrangement of their particles, this idea
is not consistently developed. For Empedocles there are only four
ultimate kinds of matter, qualitatively distinguished. The
differential qualities of all other kinds of matter must, therefore,
be due to the mixing of these four elements. Thus the qualities of the
four elements are ultimate and underived, but all other qualities must
be founded upon the position and arrangement of particles of the four
elements. This is the beginning of the mechanical explanation of
quality. But to develop this theory fully and consistently, it should
be shown, not merely that some qualities are ultimate and some {88}
derived from position and arrangement of particles, but that all
quality whatever is founded upon position and arrangement. All
becoming is explained by Empedocles as the result of motion of
material particles. To bring this mechanical philosophy to its logical
conclusion, all qualitativeness of things must be explained in the
same way. Hence it was impossible that the philosophy of mechanism and
materialism should stand still in the position in which Empedocles
left it. It had to advance to the position of Atomism. The Atomists,
therefore, maintain the essential position of Empedocles, after
eliminating the inconsistencies which we have just noted. The
philosophy of Empedocles is therefore to be considered as merely
transitional in character.
First, the Atomists developed the theory of particles. According to
Leucippus and Democritus, if matter were divided far enough, we should
ultimately come to indivisible units. These indivisible units are
called atoms, and atoms are therefore the ultimate constituents of
matter. They are infinite in number, and are too small to be
perceptible to the senses. Empedocles had assumed four different kinds
of matter. But, for the Atomists, there is only one kind. All the
atoms are composed of exactly the same kind of matter. With certain
exceptions, which I will mention in a moment, they possess no quality.
They are entirely non-qualitative, the only differences between them
being differences of quantity. They differ in size, some being larger,
some smaller. And they likewise differ in shape. Since the ultimate
particles of things thus possess no quality, all the actual qualities
of objects must be due to the {89} arrangement and position of the
atoms. This is the logical development of the tentative mechanism of
Empedocles.
I said that the atoms possess no qualities. They must, however, be
admitted to possess the quality of solidity, or impenetrability, since
they are defined as being indivisible. Moreover it is a question
whether the atoms of Democritus and Leucippus were thought to possess
weight, or whether the weight of objects is to be explained, like
other qualities, by the position and movement of the atoms. There is
no doubt that the Epicureans of a later date considered the atoms to
have weight. The Epicureans took over the atomism of Democritus and
Leucippus, with few modifications, and made it the basis of their own
teaching. They ascribed weight to the atoms, and the only question is
whether this was a modification introduced by them, or whether it was
part of the original doctrine of Democritus and Leucippus.
The atoms are bounded, and separated off from each other. Therefore,
they must be separated by something, and this something can only be
empty space. Moreover, since all becoming and all qualitativeness of
things are to be explained by the mixing and unmixing of atoms, and
since this involves movement of the atoms, for this reason also empty
space must be assumed to exist, for nothing can move unless it has
empty space to move in. Hence there are two ultimate realities, atoms
and empty space. These correspond respectively to the Being and
not-being of the Eleatics. But whereas the latter denied any reality
to not-being, the Atomists affirm that not-being, that is, empty
space, is just as real as being. Not-being also exists. "Being," said
{90} Democritus, "is by nothing more real than nothing." The atoms
being non-qualitative, they differ in no respect from empty space,
except that they are "full." Hence atoms and the void are also called
the _plenum_ and the _vacuum_.
How, now, is the movement of the atoms brought about? Since all
becoming is due to the separation and aggregation of atoms, a moving
force is required. What is this moving force? This depends upon the
question whether atoms have weight. If we assume that they have
weight, then the origin of the world, and the motion of atoms, becomes
clear. In the system of the Epicureans the original movement of the
atoms is due to their weight, which causes them to fall perpetually
downwards through infinite space. Of course the Atomists had no true
ideas of gravitation, nor did they understand that there is no
absolute up and down. The large atoms are heavier than the smaller.
The matter of which they are composed is always the same. Therefore,
volume for volume, they weigh the same. Their weight is thus
proportional to their size, and if one atom is twice as large as
another, it will also be twice as heavy. Here the Atomists made
another mistake, in supposing that heavier things fall in a vacuum
more quickly than light things. They fall, as a matter of fact, with
the same speed. But according to the Atomists, the heavier atoms,
falling faster, strike against the lighter, and push them to one side
and upwards. Through this general concussion of atoms a vortex is
formed, in which like atoms come together with like. From the
aggregation of atoms worlds are created. As space is infinite and the
atoms go on falling eternally, there must have been innumerable worlds
of which our world is only one. {91} When the aggregated atoms fall
apart again, this particular world will cease to exist. But all this
depends upon the theory that the atoms have weight. According to
Professor Burnet, however, the weight of atoms is a later addition of
the Epicureans. If that is so, it is very difficult to say how the
early Atomists, Leucippus and Democritus, explained the original
motion. What was their moving force, if it was not weight? If the
atoms have no weight, their original movement cannot have been a fall.
"It is safest to say," says Professor Burnet, "that it is simply a
confused motion this way and that." [Footnote 7] Probably this is a
very _safe_ thing to say, because it means nothing in particular. Motion
itself cannot be confused. It is only our ideas of motion which can be
confused. If this theory is correct, then, we can only say that the
Atomists had no definite solution of the problem of the origin of
motion and the character of the moving force. They apparently saw no
necessity for explanation, which seems unlikely in view of the fact
that Empedocles had already seen the necessity of solving the problem,
and given a definite, if unsatisfactory, solution, in his theory of
Love and Hate. This remark would apply to Democritus, if not to
Leucippus.
[Footnote 7: _Early Greek Philosophy_, chap. ix. Sec. 179.]
The Atomists also spoke of all movement being under the force of
"necessity." Anaxagoras was at this time teaching that all motion of
things is produced by a world-intelligence, or reason. Democritus
expressly opposes to this the doctrine of necessity. There is no
reason or intelligence in the world. On the contrary, all phenomena
and all becoming are completely determined by blind mechanical causes.
In this connection there arises {92} among the Atomists a polemic
against the popular gods and the popular religion. Belief in gods
Democritus explains as being due to fear of great terrestrial and
astronomical phenomena, such as volcanoes, earthquakes, comets, and
meteors. But somewhat inconsistently with this, Democritus believed
that the air is inhabited by beings resembling men, but larger and of
longer life, and explained belief in the gods as being due to
projection from these of images of themselves composed of atoms which
impinge upon human senses, and produce the ideas of gods.
Different kinds of matter must be explained, in any atomic theory, by
the shape, size, and position of the atoms of which they are composed.
Thus the Atomists taught that fire is composed of smooth round atoms.
The soul is also composed of smooth round atoms, and is an
exceptionally pure and refined fire. At death the soul atoms are
scattered, and hence there is, of course, no question of a future
life. Democritus also put forward a theory of perception, according to
which objects project into space images of themselves composed of
atoms. These images strike against the senses. Like atoms are
perceived by like. Thought is true when the soul is equable in
temperature. The sensible qualities of things, such as smell, taste,
colour, do not exist in the things themselves, but merely express the
manner in which they affect our senses, and are therefore relative to
us. A number of the ethical maxims of Democritus have come down to us.
But they are not based in any way upon the Atomic theory, and cannot
be deduced from it. Hence they have no scientific foundation but are
merely detached sayings, epitomizing the experience {93} and worldly
wisdom of Democritus. That one should enjoy oneself as much and vex
oneself as little as possible seems to have been his principal idea.
This, however, is not to be interpreted in any low, degraded, or
sensual way. On the contrary, Democritus says that the happiness of
man does not depend on material possessions, but upon the state of the
soul. He praises equanimity and cheerfulness, and these are best
attained, he thinks, by moderation and simplicity.
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