An editor’s capability manifests itself in the ability (which is also a duty) to envisage a manuscript covered with corrections in its pristine condition, as a blank sheet of paper, in order to recognize and establish as far as possible how this sheet was, step by step, covered with letters and symbols, with “text,” and how and why some parts of this text changed and others remained constant. The editor must therefore see the concrete development process–that is, be able to retrace and comprehend it; the editor must also interpret it–that is, be able to describe and present it.