an now yield solutions in other more complex
problems of motion which used to appear insoluble.

This modern branch of mathematics, unknown to the ancients, when dealing
with problems of motion admits the conception of the infinitely small,
and so conforms to the chief condition of motion (absolute continuity)
and thereby corrects the inevitable error which the human mind cannot
avoid when it deals with separate elements of motion instead of
examining continuous motion.

In seeking the laws of historical movement just the same thing happens.
The movement of humanity, arising as it does from innumerable arbitrary
human wills, is continuous.

To understand the laws of this continuous movement is the aim of
history. But to arrive at these laws, resulting from the sum of all
those human wills, man's mind postulates arbitrary and disconnected
units. The first method of history is to take an arbitrarily selected
series of continuous events and examine it apart from others, though
there is and can be no beginning to any event, for one event always
flows uninterruptedly from another.

The second method is to consider the actions of some one man--a king or
a commander--as equivalent to the sum of many individual wills; whereas
the sum of individual wills is never expressed by the activity of a
single historic personage.

Historical science in its endeavor to draw nearer to truth continually
takes smaller and smaller units for examination. But however small the
units it takes, we feel that to take any unit disconnected from others,
or to assume a beginning of any phenomenon, or to say that the will of
many men is expressed by the actions of any one historic personage, is
in itself false.

It needs no critical exertion to reduce utterly to dust any deductions
drawn from history. It is merely necessary to select some larger or
smaller unit as the subject of observation--as criticism has every
right to do, seeing that whatever unit history observes must always be
arbitrarily selected.

Only by taking infinitesimally small units for observation (the
differential of history, that is, the individual tendencies of men) and
attaining to the art of integrating them (that is, finding the sum of
these infinitesimals) can we hope to arrive at the laws of history.

The first fifteen years of the nineteenth century in Europe present an
extraordinary movement of millions of people. Men leave their customary
pursuits, hasten from one s