The Science Book

21

T

he nature of matter

concerned many ancient

Greek thinkers. Having

seen liquid water, solid ice, and

gaseous mist, Thales of Miletus

believed that everything must be

made of water. Aristotle suggested

that “nourishment of all things is

moist and even the hot is created

from the wet and lives by it.”

Writing two generations after

Thales, Anaximenes suggested

that the world is made of air,

reasoning that when air condenses

it produces mist, and then rain,

and eventually stones.

Born at Agrigentum on the

island of Sicily, the physician and

poet Empedocles devised a more

complex theory: that everything is

made of four roots—he did not use

the word elements—namely earth,

air, fire, and water. Combining

these roots would produce qualities

such as heat and wetness to make

earth, stone, and all plants and

animals. Originally, the four roots

formed a perfect sphere, held

together by love, the centripetal

force. But gradually strife, the

centrifugal force, began to pull

them apart. For Empedocles, love

and strife are the two forces that

shape the universe. In this world,

strife tends to predominate, which

is why life is so difficult.

This relatively simple theory

dominated European thought—

which referred to the “four

humors”—with little refinement

until the development of modern

chemistry in the 17th century. ■

THE BEGINNING OF SCIENCE

NOW HEAR THE

FOURFOLD ROOTS

OF EVERYTHING

EMPEDOCLES (490–430 BCE)

IN CONTEXT

BRANCH

Chemistry

BEFORE
c.585 BCE Thales suggests the
whole world is made of water.

c.535 BCE Anaximenes thinks
that everything is made from
air, from which water and then
stones are made.

AFTER
c.400 BCE The Greek thinker
Democritus proposes that the
world is ultimately made of tiny
indivisible particles—atoms.

1661 In his work Sceptical
Chymist, Robert Boyle provides
a definition of elements.

1808 John Dalton’s atomic
theory states that each element
has atoms of different masses.

1869 Dmitri Mendeleev
proposes a periodic table,
arranging the elements in
groups according to their
shared properties.

Empedocles saw the four roots

of matter as two pairs of opposites:

fire/water and air/earth, which

combine to produce everything we see.

Fire

Earth

Cold

Dry

Water

Wet

Hot

Air

See also: Robert Boyle 46–49 ■ John Dalton 112–13 ■ Dmitri Mendeleev 174–79