If we would know his early history, we let him tell the tale in his own fashion.

It may be he will dwell long upon occurrences interesting to himself, and apart from the object of our inquiries; it may be he will equivocate unintentionally if cross-examined in detail; but truth will underlie his garrulous story, and by patient analysis we may sift it out, and obtain the information we desire.
A nation does not begin to write its history at the first moment of its existence.

Hence, when the chronicle is compiled which first embodies its story, tradition forms the basis.

None but an inspired historian can commence _In principio_.

The nation has passed through several generations, the people already begin to talk of "old times;" but as they are nearer these "old times" by some thousands of years than we are, they are only burdened with the traditions of a few centuries at the most; and unless there is evidence of a wilful object or intent to falsify their chronicles, we may in the main depend on their accuracy.
Let us see how this applies to Gaedhilic history.