A.E. Housman, Manilii Astronomica, Vol. V (Introduction)
“The first virtue of an emendation is to be true , but the best emendations of all are those which are both true and difficult, emendations which no fool could find. It is humiliating to reflect how many of the type commonly called brilliant,- neat and pretty changes of a letter or two -, have been lighted upon, almost fortuitously, by scholars whose intellectual powers were beneath the ordinary. Textual criticism would indeed be a paradise if scribes had confined themselves to making mistakes which Isaac Voss and Robinson Ellis could correct. But we know by comparing one MS with another that they also made mistakes of a different character: and it is these that put a good emendator on his mettle. First he must recognize them, then he must deal with them suitably. Anxious adherence to the ductus litterarum is the fruitful parent of false conjectures. It seduced even such men as Scaliger and Porson: it led Scaliger to write ultimus ex solido tetrans in IV 757; it made Porson spoil his famous correction of Eur. Ion 1115 by omitting a necessary particle. The merits essential to a correction are those without which it cannot be true, and closeness to the MSS is not one of them; the indispensable things are fitness to the context and propriety to the genius of the author. The question whether the error presupposed was great or small is indeed a question to be asked, but it is the last question. With vulgar judges it is the first, though usually the last as well. This detail is their favorite criterion, because it can be discerned, or they think it can, by a bodily sense, without disturbing the slumbers of the intellect.
It surprises me that so many people should feel themselves qualified to weigh conjectures in their balance and to pronounce them good or bad, probable or improbable. Judging an emendation requires in some measure the same qualities as emendation itself, and the requirement is formidable. To read attentively, think correctly, omit no relevant consideration, and repress self-will, are not ordinary accomplishments; yet an emendator needs much besides: just literary perception, congenial intimacy with the author, experience which must have been won by study, and mother wit which he must have brought from his mother’s womb.
It may be asked whether I think that I myself possess this outfit, or even most of it; and if I answer yes, that will be a new example of my notorious arrogance. I had rather be arrogant than impudent. I should not have undertaken to edit Manilius unless I had believed that I was fit for the task; and in particular I think myself a better judge of emendation, both when to emend and how to emend, than most others.”