no contributions to the conceptions of life and of the world which the
countries of their conquest came to hold (and the evidence of language
points, indeed, to some such contributions), but their quota appears to
be small compared with that of their predecessors; nor is this
surprising, in view of the immense period during which the lands of their
conquest had been previously occupied. Nothing is clearer than the
marvellous persistence of traditional and immemorial modes of thought,
even in the face of conquest and subjugation, and, whatever ideas on
religion the Aryan conquerors of Celtic lands may have brought with them,
they whose conquests were often only partial could not eradicate the
inveterate beliefs of their predecessors, and the result in the end was
doubtless some compromise, or else the victory of the earlier faith.

But the Aryan conquerors of Gaul and Italy themselves were not men who
had advanced up the Danube in one generation. Those men of Aryan speech
who poured into the Italian peninsula and into Gaul were doubtless in
blood not unmixed with the older inhabitants of Central Europe, and had
entered into the body of ideas which formed the religious beliefs of the
men of the Danube valley. The common modifications of the Aryan tongue,
by Italians and Celts alike, as compared with Greek, suggests contact
with men of different speech. Among the names of Celtic gods, too, like
those of other countries, we find roots that are apparently irreducible
to any found in Indo-European speech, and we know not what pre-Aryan
tongues may have contributed them. Scholars, to-day, are far more alive
than they ever were before to the complexity of the contributory elements
that have entered into the tissue of the ancient religions of mankind,
and the more the relics of Celtic religion are investigated, the more
complex do its contributory factors become. In the long ages before
history there were unrecorded conquests and migrations innumerable, and
ideas do not fail to spread because there is no historian to record them.