He says of it, that "it may justly be reckoned among those few
battles of which a contrary event would have essentially varied
the drama of the world in all its subsequent scenes: with
Marathon, Arbela, the Metaurus, Chalons, and Leipsic." It was the
perusal of this note of Hallam's that first led me to the
consideration of my present subject. I certainly differ from
that great historian as to the comparative importance of some of
the battles which he thus enumerates, and also of some which he
omits. It is probable, indeed, that no two historical inquirers
would entirely agree in their lists of the Decisive Battles of
the World. Different minds will naturally vary in the
impressions which particular events make on them; and in the
degree of interest with which they watch the career, and reflect
on the importance, of different historical personages. But our
concurrence in our catalogues is of little moment, provided we
learn to look on these great historical events in the spirit
which Hallam's observations indicate. Those remarks should teach
us to watch how the interests of many states are often involved
in the collisions between a few; and how the effect of those
collisions is not limited to a single age, but may give an
impulse which will sway the fortunes of successive generations of
mankind. Most valuable also is the mental discipline which is
thus acquired, and by which we are trained not only to observe
what has been, and what is, but also to ponder on what might have
been. [See Bolingbroke, On the Study and Use of History, vol.
ii. p. 497 of his collected works.]

We thus learn not to judge of the wisdom of measures too
exclusively by the results. We learn to apply the juster