Diels helped to import the term Presocratic into classical scholarship and developed the Diels–Kranz numbering system for ancient Greek Pre-Socratic texts.

[3] He was the co-founder of Archiv für Geschichte der Philosophie in 1888 and edited Commentaria in Aristotelem Graeca at the Prussian Academy of Sciences from 1877 to 1909.

It consists of three volumes that present, for each of the Presocratics, both quotations from their (now mostly lost) works transmitted by later writers, and secondary-source material known as testimonia.

In spite of the respect paid to Diels' monumental work, there is ongoing controversy among scholars over the details of his arrangement of the fragments.

For example, some fragments categorized by Diels as quotations are thought by some scholars to be in reality only paraphrases or explanations of the Presocratic work in question.

An English translation or paraphrase of each of the B-fragments in Diels–Kranz may be found in Kathleen Freeman's Ancilla to the Pre-Socratic Philosophers (Oxford, 1948; Harvard U.