Outlines of the Earths History | Page 4

theory. It is in this effort to secure
proof that modern science has gathered the enormous store of
well-ascertained facts which constitutes its true wealth, and which
distinguishes it from the earlier imaginative and to a great extent
unproved views.
In the original state of learning, natural science was confounded with
political and social tradition, with the precepts of duty which constitute
the law of the people, as well as with their religion, the whole being in
the possession of the priests or wise men. So long as natural action was
supposed to be in the immediate control of numerous gods and
demigods, so long, in a word, as the explanation of Nature was what we
term polytheistic, this association of science with other forms of
learning was not only natural but inevitable. Gradually, however, as the

conception of natural law replaced the earlier idea as to the intervention
of a spirit, science departed from other forms of lore and came to
possess a field to itself. At first it was one body of learning. The
naturalists of Aristotle's time, and from his day down to near our own,
generally concerned themselves with the whole field of Nature. For a
time it was possible for any one able and laborious man to know all
which had been ascertained concerning astronomy, chemistry, geology,
as well as the facts relating to living beings. The more, however, as
observation accumulated, and the store of facts increased, it became
difficult for any one man to know the whole. Hence it has come about
that in our own time natural learning is divided into many distinct
provinces, each of which demands a lifetime of labour from those who
would know what has already been done in the field, and what it is now
important to do in the way of new inquiries.
The large divisions which naturalists have usually made of their tasks
rest in the main on the natural partitions which we may readily observe
in the phenomenal world. First of all comes astronomy, including the
phenomena exhibited in the heavens, beyond the limits of the earth's
atmosphere. Second, geology, which takes account of all those actions
which in process of time have been developed in our own sphere. Third,
physics, which is concerned with the laws of energy, or those
conditions which affect the motion of bodies, and the changes which
are impressed upon them by the different natural forces. Fourth,
chemistry, which seeks to interpret the principles which determine the
combination of atoms and the molecules which are built of them under
the influence of the chemical affinities. Fifth, biology, or the laws of
life, a study which pertains to the forms and structures of animals and
plants, and their wonderful successions in the history of the world.
Sixth, mathematics, or the science of space and number, that deals with
the principles which underlie the order of Nature as expressed at once
in the human understanding and in the material universe. By its use
men were made able to calculate, as in arithmetic, the problems which
concern their ordinary business, as well as to compute the movements
of the celestial bodies, and a host of actions which take place on the
earth that would be inexplicable except by the aid of this science. Last
of all among the primary sciences we may name that of psychology,

which takes account of mental operations among man and his lower
kindred, the animals.
In addition to the seven sciences above mentioned, which rest in a great
measure on the natural divisions of phenomena, there are many, indeed,
indefinitely numerous, subdivisions which have been made to suit the
convenience of students. Thus astronomy is often separated into
physical and mathematical divisions, which take account either of the
physical phenomena exhibited by the heavenly bodies or of their
motions. In geology there are half a dozen divisions relating to
particular branches of that subject. In the realm of organic life, in
chemistry, and in physics there are many parts of these sciences which
have received particular names.
It must not be supposed that these sciences have the independence of
each other which their separate names would imply. In fact, the student
of each, however, far he may succeed in separating his field from that
of the other naturalists, as we may fitly term all students of Nature, is
compelled from time to time to call in the aid of his brethren who
cultivate other branches of learning. The modern astronomer needs to
know much of chemistry, or else he can not understand many of his
observations on the sun. The geologists have to share their work with
the student of animal and vegetable life, with the physicists; they must,
moreover, know something of the celestial spheres in order to