Timaeus
three first regular solids are formed—first, the equilateral
pyramid or tetrahedron; secondly, the octahedron; thirdly, the
icosahedron; and from the isosceles triangle is formed the cube.
And there is a fifth figure (which is made out of twelve
pentagons), the dodecahedron—this God used as a model for the
twelvefold division of the Zodiac.
Let us now assign the geometrical forms to their respective
elements. The cube is the most stable of them because resting on
a quadrangular plane surface, and composed of isosceles
triangles. To the earth then, which is the most stable of bodies
and the most easily modelled of them, may be assigned the form of
a cube; and the remaining forms to the other elements,—to fire
the pyramid, to air the octahedron, and to water the
icosahedron,—according to their degrees of lightness or heaviness
or power, or want of power, of penetration. The single particles
of any of the elements are not seen by reason of their smallness;
they only become visible when collected. The ratios of their
motions, numbers, and other properties, are ordered by the God,
who harmonized them as far as necessity permitted.
The probable conclusion is as follows:—Earth, when dissolved by
the more penetrating element of fire, whether acting immediately
or through the medium of air or water, is decomposed but not
transformed. Water, when divided by fire or air, becomes one part
fire, and two parts air. A volume of air divided becomes two of
fire. On the other hand, when condensed, two volumes of fire make
a volume of air; and two and a half parts of air condense into
one of water. Any element which is fastened upon by fire is cut
by the sharpness of the triangles, until at length, coalescing
with the fire, it is at rest; for similars are not affected by
similars. When two kinds of bodies quarrel with one another, then
the tendency to decomposition continues until the smaller either
escapes to its kindred element or becomes one with its conqueror.
And this tendency in bodies to condense or escape is a source of
motion...Where there is motion there must be a mover, and where
there is a mover there must be something to move. These cannot
exist in what is uniform, and therefore motion is due to want of
uniformity. But then why, when things are divided after their
kinds, do they not cease from motion? The answer is, that the
circular motion of all things compresses them, and as ‘nature
abhors a vacuum,’ the finer and more subtle particles of the
lighter elements, such as fire and air, are thrust into the
interstices of the larger, each of them penetrating according to
their rarity, and thus all the elements are on their way up and
down everywhere and always into their own places. Hence there is
a principle of inequality, and therefore of motion, in all time.
In the next place, we may observe that there are different kinds
of fire—(1) flame, (2) light that burns not, (3) the red heat of
the embers of fire. And there are varieties of air, as for
example, the pure aether, the opaque mist, and other nameless
forms. Water, again, is of two kinds, liquid and fusile. The
liquid is composed of small and unequal particles, the fusile of
large and uniform particles and is more solid, but nevertheless
melts at the approach of fire, and then spreads upon the earth.
When the substance cools, the fire passes into the air, which is
displaced, and forces together and condenses the liquid mass.
This process is called cooling and congealment. Of the fusile
kinds the fairest and heaviest is gold; this is hardened by
filtration through rock, and is of a bright yellow colour. A
shoot of gold which is darker and denser than the rest is called
adamant. Another kind is called copper, which is harder and yet
lighter because the interstices are larger than in gold. There is
mingled with it a fine and small portion of earth which comes out
in the form of rust. These are a few of the conjectures which
philosophy forms, when, leaving the eternal nature, she turns for
innocent recreation to consider the truths of generation.
Water which is mingled with fire is called liquid because it
rolls upon the earth, and soft because its bases give way. This
becomes more equable when separated from fire and air, and then
congeals into hail or ice, or the looser forms of hoar frost or
snow. There are other waters which are called juices and are
distilled through plants. Of these we may mention, first, wine,
which warms the soul as well as the body; secondly, oily
substances, as for example, oil or pitch; thirdly, honey, which
relaxes the contracted parts of the mouth and so produces
sweetness; fourthly, vegetable acid, which is frothy and has a
burning quality and dissolves the flesh. Of the kinds of earth,
that which is filtered through water passes into stone; the water
is broken up by the earth and escapes in the form of air—this in
turn presses upon the mass of earth, and the earth, compressed
into an indissoluble union with the remaining water, becomes
rock. Rock, when it is made up of equal particles, is fair and
transparent, but the reverse when of unequal. Earth is converted
into pottery when the watery part is suddenly drawn away; or if
moisture remains, the earth, when fused by fire, becomes, on
cooling, a stone of a black colour. When the earth is finer and
of a briny nature then two half-solid bodies are formed by
separating the water,—soda and salt. The strong compounds of
earth and water are not soluble by water, but only by fire. Earth
itself, when not consolidated, is dissolved by water; when
consolidated, by fire only. The cohesion of water, when strong,
is dissolved by fire only; when weak, either by air or fire, the
former entering the interstices, the latter penetrating even the
triangles. Air when strongly condensed is indissoluble by any
power which does not reach the triangles, and even when not
strongly condensed is only resolved by fire. Compounds of earth
and water are unaffected by water while the water occupies the
interstices in them, but begin to liquefy when fire enters into
the interstices of the water. They are of two kinds, some of
them, like glass, having more earth, others, like wax, having
more water in them.
Having considered objects of sense, we now pass on to sensation.
But we cannot explain sensation without explaining the nature of
flesh and of the mortal soul; and as we cannot treat of both
together, in order that we may proceed at once to the sensations
we must assume the existence of body and soul.
What makes fire burn? The fineness of the sides, the sharpness of
the angles, the smallness of the particles, the quickness of the
motion. Moreover, the pyramid, which is the figure of fire, is
more cutting than any other. The feeling of cold is produced by
the larger particles of moisture outside the body trying to eject
the smaller ones in the body which they compress. The struggle
which arises between elements thus unnaturally brought together
causes shivering. That is hard to which the flesh yields, and
soft which yields to the flesh, and these two terms are also
relative to one another. The yielding matter is that which has
the slenderest base, whereas that which has a rectangular base is
compact and repellent. Light and heavy are wrongly explained with
reference to a lower and higher in place. For in the universe,
which is a sphere, there is no opposition of above or below, and
that which is to us above would be below to a man standing at the
antipodes. The greater or less difficulty in detaching any
element from its like is the real cause of heaviness or of
lightness. If you draw the earth into the dissimilar air, the
particles of earth cling to their native element, and you more
easily detach a small portion than a large. There would be the
same difficulty in moving any of the upper elements towards the
lower. The smooth and the rough are severally produced by the
union of evenness with compactness, and of hardness with
inequality.
Pleasure and pain are the most important of the affections common
to the whole body. According to our general doctrine of
sensation, parts of the body which are easily moved readily
transmit the motion to the mind; but parts which are not easily
moved have no effect upon the patient. The bones and hair are of
the latter kind, sight and hearing of the former. Ordinary
affections are neither pleasant nor painful. The impressions of
sight afford an example of these, and are neither violent nor
sudden. But sudden replenishments of the body cause pleasure, and
sudden disturbances, as for example cuttings and burnings, have
the opposite effect.
>From sensations common to the whole body, we proceed to those of
particular parts. The affections of the tongue appear to be
caused by contraction and dilation, but they have more of
roughness or smoothness than is found in other affections. Earthy
particles, entering into the small veins of the tongue which
reach to the heart, when they melt into and dry up the little
veins are astringent if they are rough; or if not so rough, they
are only harsh, and if excessively abstergent, like potash and
soda, bitter. Purgatives of a weaker sort are called salt and,
having no bitterness, are rather agreeable. Inflammatory bodies,
which by their lightness are carried up into the head, cutting
all that comes in their way, are termed pungent. But when these
are refined by putrefaction, and enter the narrow veins of the
tongue, and meet there particles of earth and air, two kinds of
globules are formed—one of earthy and impure liquid, which boils
and ferments, the other of pure and transparent water, which are
called bubbles; of all these affections the cause is termed acid.
When, on the other hand, the composition of the deliquescent
particles is congenial to the tongue, and disposes the parts
according to their nature, this remedial power in them is called
sweet.
Smells are not divided into kinds; all of them are transitional,
and arise out of the decomposition of one element into another,
for the simple air or water is without smell. They are vapours or
mists, thinner than water and thicker than air: and hence in
drawing in the breath, when there is an obstruction, the air
passes, but there is no smell. They have no names, but are
distinguished as pleasant and unpleasant, and their influence
extends over the whole region from the head to the navel.
Hearing is the effect of a stroke which is transmitted through
the ears by means of the air, brain, and blood to the soul,
beginning at the head and extending to the liver. The sound which
moves swiftly is acute; that which moves slowly is grave; that
which is uniform is smooth, and the opposite is harsh. Loudness