full re-examination becomes necessary; and the result, especially if similar instances recur, may be the discovery of some genealogical complication overlooked before. No definite rule can be given as to what should be done where the apparent conflict remains, more especially where the documentary evidence is scanty or obscure. For our own part, in any writing having fairly good and various documentary attestation we should think it dangerous to reject any reading clearly supported by genealogical relations, though we might sometimes feel it equally necessary to abstain from rejecting its rival.
82. Next in value to Genealogical Evidence is Internal Evidence of Documents, single or in groups. But where the documents exceed a very small number, the Internal Evidence of single Documents, as has already been explained (§ 48), is rendered for the most part practically inapplicable by the unresolved complexity. The Internal Evidence however of Groups of Documents is always applicable if there are documents enough to form groups. It is the best substitute for Genealogical Evidence proper in texts, or in any parts of texts, in which genealogical relations are too obscure for use; and it affords the most trustworthy presumptions for comparison with purely genealogical presumptions, having similar merits derived from the form of the processes by which it is obtained, while relating to a different class of phenomena. The highest certainty is that which arises from concordance of the presumptions suggested by all methods, and it is always prudent to try every variation by both kinds of Internal Evidence of Readings. The uncertainty however inherent in both, as dependent on isolated acts of individual judgement, renders them on the whole untrustworthy against a con-
