ho was in great perplexity at
the turn events were taking, representing to him that there was nothing
the people called Christians could not obtain by their prayers, and
that among his forces was a troop composed wholly of followers of that
religion. Rejoiced at this news, Marcus Antoninus demanded of these
soldiers that they should pray to their god, who granted their petition
on the instant, sent lightning among the enemy and consoled the Romans
with rain. Struck by this wonderful success, the emperor honored the
Christians in an edict and named their legion The Thundering. It is even
asserted that a letter existed by Marcus Antoninus on this subject.
The pagans well knew that the company was called The Thunderers, having
attested the fact themselves, but they revealed nothing of the occasion
on which the leader received the name."(1)

Peculiar interest attaches to this narrative as illustrating both
credulousness as to matters of fact and pseudo-scientific explanation
of alleged facts. The modern interpreter may suppose that a violent
thunderstorm came up during the course of a battle between the Romans
and the so-called barbarians, and that owing to the local character of
the storm, or a chance discharge of lightning, the barbarians
suffered more than their opponents. We may well question whether the
philosophical emperor himself put any other interpretation than this
upon the incident. But, on the other hand, we need not doubt that the
major part of his soldiers would very readily accept such an explanation
as that given by Dion Cassius, just as most readers of a few centuries
later would accept the explanation of Xiphilinus. It is well to bear
this thought in mind in considering the static period of science upon
which we are entering. We shall perhaps best understand this period, and
its seeming retrogressions, if we suppose that the average man of the
Middle Ages was no more credulous, no more superstitious, than the
average Roman of an earlier period or than the average Greek; though the
precise complexion of his credulity had changed under the influence of
Oriental ideas, as we have just seen illustrated by the narrative of
Xiphilinus.

APPENDIX

REFERENCE LIST, NOTES, AND BIBLIOGRAPHIES

CHAPTER I. PREHISTORIC SCIENCE

Length of the Prehistoric Period.--It is of course quite impossible to
reduce the prehistoric period to any definite number of years. There
are, however, numerous bits of evidenc