The Science Book

23

A

Persian scholar born in

Baghdad in 1201, during

the Golden Age of Islam,

Nazir al-Din al-Tusi was a poet,

philosopher, mathematician, and

astronomer, and one of the first to

propose a system of evolution. He

suggested that the universe had

once comprised identical elements

that had gradually drifted apart,

with some becoming minerals and

others, changing more quickly,

developing into plants and animals.

In Akhlaq-i-Nasri, al-Tusi’s work

on ethics, he set out a hierarchy of

life forms, in which animals were

higher than plants and humans

were higher than other animals.

He regarded the conscious will

of animals as a step toward the

consciousness of humans. Animals

are able to move consciously to

search for food, and can learn

new things. In this ability to learn,

al-Tusi saw an ability to reason:

“The trained horse or hunting

falcon is at a higher point of

development in the animal world,”

he said, adding, “The first steps of

human perfection begin from here.”

Al-Tusi believed that organisms

changed over time, seeing in that

change a progression toward

perfection. He thought of humans

as being on a “middle step of the

evolutionary stairway,” potentially

able by means of their will to reach

a higher developmental level. He

was the first to suggest that not

only do organisms change over

time, but that the whole range of

life has evolved from a time when

there was no life at all. ■

THE BEGINNING OF SCIENCE

THE HUMAN IS

RELATED TO THE

LOWER BEINGS

AL-TUSI (1201–1274)

IN CONTEXT

BRANCH

Biology

BEFORE
c.550 BCE Anaximander of
Miletus proposes that animal
life began in the water, and
evolved from there.

c.340 BCE Plato’s theory of
forms argues that species
are unchangeable.

c.300 BCE Epicurus says that
many other species have been
created in the past, but only
the most successful survive
to have offspring.

AFTER
1377 Ibn Khaldun writes in
Muqaddimah that humans
developed from monkeys.

1809 Jean-Baptiste Lamarck
proposes a theory of evolution
of species.

1858 Alfred Russel Wallace
and Charles Darwin suggest
a theory of evolution by means
of natural selection.

The organisms that can

gain the new features faster

are more variable. As a result,

they gain advantages

over other creatures.

al-Tusi

See also: Carl Linnaeus 74–75 ■ Jean-Baptiste Lamarck 118 ■

Charles Darwin 142–49 ■ Barbara McClintock 271