The Cambridge History of English and American Literature in 18 Volumes (1907–21).
Volume IV. Prose and Poetry: Sir Thomas North to Michael Drayton.
§ 8. The later Folios
The value of the later folios is comparatively small. They take great liberties with the text, though, it must be admitted, not beyond those taken by some of the later editors. When the second folio makes an alteration, this is, as a rule, perpetuated in the third and fourth. Where the second or third stands alone, it is nearly always wrong. The fourth folio is not so free in making alterations, except in order to modernise the spelling. Were it not for the legacy of errors inherited from the second and third, the fourth would often be nearer a modern text than either. The later folios, however, have all made some happy restorations of the text. In the case of the variant quarto plays, where a later folio agrees with the quarto against the first, we have a better attested reading. There are some remarkable cases of this coincidence.
One cause of variation between the different quarto and folio texts remains to be noted. It is the most prolific and the most modern of all—the mistakes of editor and printer.