It has often been assumed that conjecture is involved only when an editor reconstructs or creates a reading which is not extant in any of the witnesses; but the choice among extant variants is just as critical, and just as ultimately conjectural, as the recreation of a form which happens not to be extant in any of the witnesses.
Konjektur (lat. coniectura ‘Vermutung’) Eingriff des Editors bei einer Textverderbnis, wenn zu vermuten ist, daß auf diese Weise der originale Text wiederhergestellt werden kann.