 Diels saw the development from Theophrastus to these later and (in his view) dependent authors as a decline, and a progressive obfuscation and deterioration. His cladistic reconstruction of the doxographical tradition is clearly related to the famous so-called ‘Lachmannian’ stemma of a group of manuscripts, from later copies to the lost common ancestor, or archetype, the text of which (as scholars believed at the time) may be reconstructed in a virtually mechanical way. Diels was very much aware of this analogy, which surely was an important factor in convincing him and others that the splendid results of his investigations were irrefutable. In the 19th century the method attributed to Lachmann was assumed to be beyond criticism.