t by which
appropriate limbs fastened themselves to the proper animals. The last
of these misjointed creatures is the one known as the centaur,
half-man--half-horse. After a while, when all the members had found
their proper places, the animals were complete. In one respect this
opinion foreshadowed our later idea. It suggested that the more
perfect animals had arisen out of the less perfect and that the change
came gradually.

Then came Anaxagoras, who was the first to believe that there was
intelligent design back of the creation of animals and of plants. He
thought there had originally been a slime in which were the germs of
all the later plants, animals, and minerals, mixed in a chaos. Slowly
order arose. Out of the mixture settled first the minerals forming the
earth, with the air floating above it, and above the air was the
ether. Out of the air the germs of plants settled upon the earth, and
vegetation covered the mineral floor. Then from the ether came the
germs of animals and of men. These settled among the plants and sprang
up into the animals of the world, as well as the people.

The greatest scientific thinker of early Greece was Aristotle. He had
lived by the seashore and knew better than any other man of his times
the exquisite seaweeds and the still more beautiful marine animals. He
was the first to think of them as a linked series, the higher
developing out of the lower under the pressure of what he called a
perfecting principle. Out of the inanimate rocks had sprung the marine
plants--the seaweeds. From these had developed first "plant animals"
like the sea anemones and the sponges. These grew attached to the
rocks, as plants do. With higher development came locomotion, with
ever-increasing energy. At last man arose, the crown of all creation.
Presiding over all this advance is the "efficient cause," God.
Aristotle rejected entirely the earlier ideas that any of this work
came about by chance. He was certain of the existence of plan and
purpose in the development.

Just a little before the time of Christ the Latin poet, Lucretius,
wrote a poem on "The Nature of Things." Here he describes how in the
early years the beginnings of things in small, disjointed fashion
moved about among each other at first in utter confusion, each trying
itself with the other. After many trials the proper members came
together. When they had been thus placed the warmth of the sun shining
down upon the earth helped the ear