THE ELEATIC VIEW
One of the problems that early perplexed the human mind was that of
motion. Parmenides, of the Eleatic school, could not conceive of
movement of bodies without vacuous space, and for him there could be no
vacuum, since the universe is a _plenum_--the All, the One. Hence
there could be no motion, movement of bodies and physical changes being
mere delusive appearances.
Leucippus granted that he, likewise, could not conceive of the motion
of bodies unless there was empty space for them to move in. But motion
he recognized as a fact of nature, as a reality. The Eleatics must,
therefore, he said, be in error in supporting the premise that “there
is no vacuum.” Given empty space, motion followed.
Neither Parmenides nor Leucippus introduced the conception of the
vacuum. It was a pre-existing doctrine fervently attacked by Parmenides
and supported on logical grounds by Leucippus. “Nor,” says Professor
Gompertz of Leucippus, “did he do more than to refine and to raise to
the dignity of a self-sustained system the atomic theory which existed
before him, though in a rude, rudimentary and imperfect shape.”
Given atoms of various sizes and forms, their movement in vacuous
space was taken as much for granted as their existence. Just as matter
itself had no beginning, and can have no ending, so the natural and
original condition of atoms was a state of motion. The state of rest
was no more “natural” to the Atomists than was the state of motion.
They knew nothing of the doctrine which regards matter as an “inert
mass.” Matter for them was essentially active and non-quiescent, as it
was centuries later for Bruno, Bacon, Leibnitz, Spinoza, and as it is
in our own times for all physicists. For _energy_ is synonymous
with _motion_, and matter itself is but a collection of _energy
units_ (in constant motion).
DEMOCRITUS’ THEORY
According to Democritus the atoms fall with varying degrees of
rapidity, the heavier particles faster, the lighter with less speed,
the heavier overtaking and striking against the lighter ones. To quote
Lange’s succinct statement:
“As the atoms are of various shapes, and the collision will not
take place in the center of the atoms, then, even according to the
principles of modern mechanical science, revolutions of the atoms
on their axes and lateral motions will be set up. When once set up,
these lateral motions must ever become more and more complicated, and
as the collision of constant new atoms with a layer of atoms already
in lateral motion constantly imparts new forces, so we may suppose
that the motion will continually increase. From the lateral motions
in connection with the rotation of the atoms are then easily produced
cases of retrogressive movement. If now, in a layer of atoms so
involved, the heavier--i. e., the larger--atoms continually receive a
stronger impetus downwards, they will finally be collected below, while
the light ones will form the upper stratum.”[15]
Aristotle said that if there could be such a condition as space
devoid of substance (matter), then in such a vacuum all bodies, light
or heavy, would fall with equal velocity, which he considered an
absurdity. For him the differences in the speed of falling bodies are
entirely dependent upon differences in the density of the medium--air
or water--through which they fall toward the center of the earth.
Epicurus agreed with the Stagirite on the point of equal velocities in
a non-resisting medium. But Aristotle not only denied the possibility
of the existence of a void anywhere, but asserted that in such a
void--were a vacuum possible--no motion could take place!
Epicurus believed that all atoms, of whatever weight, would fall with
equal velocity in a vacuum, in simple parallel lines. They are in
everlasting movement, originally a perpetual, equable falling through
the boundless infinity of vacuous space, with an incomparably greater
speed than that of light-rays; though he believed that these traverse
the distance from sun to earth in an instant.[16]
While it is true that in infinite space there is neither an “up” nor
a “down,” the fact remains, as Epicurus in effect observed, that man
considers his head “up” and his feet “down,” and a body as being
relatively distant from, or as near or on or within, the earth. So the
atoms do converge at the earth, falling downwards unless met by bodies
which, by a particular movement and weight, drive them to one side or
upwards, or in a spiral or whirling motion--“the commencement of the
formation of worlds.” But if the movement of atoms is in straight
parallel lines, and all move in the vacuum with equal velocity, how
could one atom drive another “to one side or upwards”?
Just here is where the weakness in the atomic theory is introduced by
Epicurus. Democritus accounted for the collision and rebound of atoms
under law, by a _cause_, not by chance. Epicurus threw away the
cause and introduced “chance collisions.” But no atom was ever deviated
from its flight in parallel lines by “chance”--in this case a wholly
metaphysical invention. No worlds, no suns or planets could be built up
on the theory of particles falling through infinite space in parallel
rectilinear paths. There must be collision and recoil of atoms in order
that the lateral and whirling movements, or vortices, should be set up,
which were supposed to cause the atoms to combine according to their
shape, size, and weight, the heavier forming the denser portions of the
earth, the lighter constituting the atmosphere.
This difficulty did not escape the astute mind of Lucretius. But
in attempting to solve what is really an insoluble problem--the
development of worlds under the conditions stated--the great Roman poet
only made bad matters worse. For here he introduced the dogma of free
will applied to the falling atoms. They were made to deviate from
their parallel lines by a voluntary movement!
And it appears that this was done on the authority of Epicurus himself:
“In these errors,” says Lange, “Democritus probably had no share;
and yet we shall judge them more leniently if we reflect that, even
to our own day, the essence of the doctrine of the freedom of the
will, with whatever metaphysical subtlety it is elaborated, consists
simply of the uncertainty and perplexity of phenomenal appearances.”
Again: “Whilst, therefore, it is one of the most important efforts of
recent materialism to deduce the whole mass of voluntary movements
from mechanical causes, we find Epicurus adopting a quite incalculable
element into his system.”[17]
For Democritus a “chance” occurrence would be a causeless event, and
this he could not allow under his law of “necessity.” An efficient
cause produces always appropriate and calculable results under
given conditions, and these results are always uniform, predictable
occurrences, given knowledge of the mechanical factors involved.
To the earlier Atomists it seemed clear that particles which are alike
in weight and in form would “naturally,” when whirled about in a
vortex, be brought to the same location; and because of their peculiar
shape, become entangled one with another. Since some atoms were
supplied with hooks or even with balls and sockets, some with mortice
or dovetail, others with sharp, rough or involuted edges, what more
“natural” than that groups or combinations of atoms should be formed,
even to the cohesion of some atoms in places not suitable to their
nature, resulting in the formation of compound bodies?
Some atoms, indeed, were “unsociable,” having no means of mutual
attachment; hence their combination was effected by enclosing them in
a shell formed by the “social” particles. Some atoms had means for
attachment at two points, which accounts, in part, for the greater or
less mobility of the various atoms. The soul consists of the finest
and smoothest atoms, akin to those of fire; and since they penetrate
the whole body, their motions give rise to the phenomena of life.
All objects project into space images of themselves, composed of
atoms, which strike against the senses, and are perceived by similar
atoms--“like atoms are perceived by like.”
These assumptions were wholly unacceptable to the critical mind
of Aristotle,[18] as well as to his distinguished disciple, Strato
of Lampsacus, teacher of Ptolemy Philadelphus. The Roman Stoic,
Cicero, regarded the Democritean theory of cohesion and compounding
of substances as wholly fantastic.[19] Yet the critics of Democritus
had no better theory to offer in its place, since they, like the
Atomists themselves, had no conception of the electrical, chemical or
gravitational attraction of bodies for each other, or of the fact that
the pressure of the atmosphere causes the ascent of fire, vapor and
heated molecules in general.
To the foregoing objections, others might be offered, but we add only
that in modern terms, the impact of indivisible and indeformable atoms
upon one another could not produce the required movement of elementary
masses. For “if the atoms are rigid, transmission of motion through
impact is impossible; if they are elastic, they are then deformable
and composed of parts, which is contrary to the hypothesis and implies
forces of cohesion and elasticity.”[20]
Democritus, though he was the greatest physicist of his age, could
not, of course, be expected to anticipate our modern objections to his
doctrine--or his master’s doctrine. The immortal Newton (1642-1727)
himself, even Dalton (1766-1844), founder of the modern chemical
atomic theory (as distinguished from the _physical_ atomic
theories of his predecessors), could not anticipate the advances that
have made possible the relentless criticism of modern physics and
chemistry. Newton, Boyle and Huygens had no idea that the “atoms” of
their conceptions were occupied mostly by “empty space” (using this
phrase in its popular meaning--modern science recognizing no actually
empty space: for all space contains a gravitational “ether” if not an
electromagnetic field of energy).
Thus the “atom” of the chemist is a highly elastic body--highly
resilient. Moreover, thanks to the genius of Professor Frederick Soddy,
of Oxford, and of Sir F. W. Aston, we now know that what we considered
but three years ago to be a homogeneous element--e.g., lead, chlorine,
carbon, iron, etc.--is in many cases--if not in all cases excepting
hydrogen and helium--a compound body containing particles of different
weights (atomic mass). On the other hand, as previously stated, we are
reverting to the Democritean theory that all atoms are composed of but
one primitive element, the hydrogen atom. And the hydrogen atom in
turn is composed of--_energy_; and energy itself is apparently of
atomic structure. All energy is, in the last analysis, electrical in
nature, the stuff that lightning, the stars, fire, rocks and metals,
the bodies of plants and animals--perhaps the mind of man--are all made
of.
With these facts in mind, let us return to Democritus, whose
errors--the errors of his age--we may now regard with due allowances.
“SOUL ATOMS”
With Democritus, as with Pythagoras and Heraclitus, fire had a special
importance, though it was not, as asserted by some of the ancient
writers, regarded by him as an element. The primitive substance, the
source of all things, whether fire, earth, air or water, was the world
of homogeneous atoms, eternal, unchangeable. Fire, composed of minute,
round, smooth atoms, was, on account of its mobility, the living and
moving principle of nature, though not the direct _cause_ of
motion. But because of the fiery, mobile nature of its atoms, they
become a secondary cause of additional motion, from their impact with
and recoil from less mobile atoms. Sensation and consciousness are
possible because of the extreme mobility of the fiery atoms. They are
the “soul atoms,” but sensibility and consciousness arise only as the
result of relatively large aggregations of these excessively minute
bodies.
“EFFLUENCES”
In order to account for the mutual action or influence of bodies upon
one another, when separated by space,--the void,--the Atomists had
recourse to the Empedoclean theory of “effluences,” or emanations,
which were supposed to be emitted by all bodies (Aristotle,
_Generatio et Corruptio_, i, 8). Penetrating the organs of sense,
they excite the appropriate sensation, and, in the case of the brain,
they produce images or ideas of things. Hence sensation is the only
possible source of knowledge, the origin of all thought being the
passage through the sense organs of “effluences” from external objects
or organisms, acting mechanically, by contact.
But while affirming that sensation is the source of all knowledge,
Democritus, nevertheless, agrees with the Pythagoreans and Socrates in
rejecting sensation as such as a source of knowledge. He distinguishes
between a “bastard” (_skotie_) knowledge obtained through the
special senses and a true-born (_gnesie_) knowledge, obtained by
direct-contact of external atoms with the body’s “soul atoms.” These
are not concentrated in the brain nor are they dependent upon the
organs of sense. They are diffused throughout the entire organism, and
come into direct contact, without the intervention of the deceptive
sense organs, with the reality outside our body.
“Poor Mind,” he makes the senses say (Fragment 125), “it is from us
thou hast got the proofs to throw us with. Thy throw is a fall.”[21]
As Burnet points out, the “true-born knowledge is of the same nature
as the “bastard,” and “Democritus refused, like Socrates, to make an
absolute separation between sense and thought,” the former being,
‘after all, not thought, but a sort of inner sense, and its objects are
like the ‘common sensibles’ of Aristotle.’ In the “bastard” knowledge,
Democritus included sight, hearing, smell, taste, touch. “True-born”
knowledge was obtained directly by the diffused soul atoms from the
external objects, and thus made them known as they really are. All
phenomena of life and mind are due to the motion of the mobile fiery
atoms. Even where Democritus speaks of “the Divine,” he means merely
the fiery soul atoms; not a personal being of any kind.
Where there is a large aggregation of the soul atoms, there reason
appears, itself a physical phenomenon. Democritus recognized no
_Nous_ (Anaxagoras) or World-Soul (Plato), or Deity (Aristotle).
The only motive force of the world is gravity, the soul being a
secondary cause of motion only by virtue of the fiery atoms’ being most
easily moved by pressure and contact. “Spirit” is “only one substance
moving side by side with others.”[22]
Every act of the individual, every occurrence in nature, has its
efficient cause from which it follows by necessity--or, as we should
say, under natural law. All change in things must be reduced to an
altered combination of atoms--to new forms and arrangements in space,
under the law of “necessity.”
The soul is material and disappears with the disintegration of the
body, though there exist invisible beings all around us in the air.
But these invisible beings are material bodies also, composed of the
finest atoms. At times they project images of themselves which affect
our soul atoms, rendering these aerial beings, for the time, visible
bodies.
FOOTNOTES:
[Footnote 15: Lange, Frederick Albert. “History of Materialism,” Vol.
I, Page 25, London, 1892.]
[Footnote 16: That 498 seconds, over eight minutes, are required for
this transmission of light is a discovery of the eighteenth century.]
[Footnote 17: Lange, _Op. cit._, Page 142.]
[Footnote 18: _De Caelo_, iii, 4; _Generatio et Corruptio_,
i, 21; and elsewhere.]
[Footnote 19: _Academica_, ii, 38, 121.]
[Footnote 20: Rougier, Louis, “Philosophy and the New Physics,” Pages
7-8, London, 1922.]
[Footnote 21: Burnet, Dr. John, _Op. cit._, Page 153; and Note 2,
Page 113. Dr. Burnet is Professor of Greek at St. Andrews University,
Scotland.]
[Footnote 22: Zeller, _Op. cit._, Vol. II, Page 253.]