In studies conducted among existing variants in New Testament copies, the vast majority of scholars agree that the New Testament has remained fairly stable with only many minor variants (Daniel B. Wallace, Michael J. Kruger, Craig A. Evans, Edward D Andrews, Kurt Aland, Barbara Aland, F. F. Bruce, Fenton Hort, Brooke Foss Westcott, Frederic G. Kenyon, Jack Finegan, Archibald Thomas Robertson). Some critics, such as Kurt Aland, deny that there is any basis whatever for conjectural emendation of the manuscript evidence. Bart D. Ehrman, Helmut Koester, David C. Parker believe that it is not possible to establish the original text with absolute certainty, but do not posit a systematic revision as in the Howard hypothesis.