corruption, or, which is much the commonest case, partly to the one, partly to the other. Whatever a document has inherited of the autograph text is of necessity included in its proper or ancestral text; and in order to ascertain the character of those of its singular readings which belong to its ancestral text, we must sift away as far as possible those other singular readings which are mere individualisms, so to speak, originating with the scribe or one of his immediate predecessors. Complete discrimination is of course impossible in the absence of the exemplar or exemplars; but every approximation to it is a gain. Except by conjecture, which does not concern us here, no scribe can make a text better than he found it; his highest merit is to leave it no worse. The inherited text of a document must therefore have been usually better, never worse, than the text which it actually presents to the eye; and the character of the inherited text is inevitably disguised for the worse by every 'individualism' which remains undetected.
311. Individualisms may obviously belong to various types, from purely clerical errors to alterations of purely mental origin. Sufficient clerical errors betray themselves, beyond the possibility of doubt, to enable us with a little care to form an estimate of the degree of general accuracy attained by the scribe of a given document, and also of the kinds of mistakes to which he was prone (see § 45). The mere subtraction of a large number of irrelevant readings from the gross list of singular readings gives, as we have seen, greater exactness to the appreciation of the character of the ancestral text. But moreover the further knowledge gained respecting the habits of the scribe becomes of use both positively and negatively in dealing at a later stage with individual
