Almost nothing is known of Heraclitus’ life. One can say with some assurance, however, that he lived during the period spanning the end of the sixth century and the beginning of the fifth century BC. The details of his life that are found in Diogenes Laertius are late, anecdotal, and unreliable; many seem to be merely fractured extrapolations from material found in the surviving fragments.

What we know for certain is that he grew up in one of the richest and most splendid cities in Asia Minor, Ephesus, at a time when it flourished under Persian rule. He seems, however,...

In the enumeration of the fragments [ ] indicates that the item in question is only doubtfully ascribable in its present form to Heraclitus, though it captures something of the spirit of Heraclitus’ thought; ? indicates that the item is doubtfully ascribable to Heraclitus at all. In the translations of the fragments 〈 〉 indicates what seems to be a natural addition in English to make sense of the Greek text; [ ] indicates either the immediate context of the fragment or what looks like a comment or query or explanation on the part of the author quoting Heraclitus; (...

References to well-known editions and critical studies of the works of Heraclitus and of other ancient sources (Reinhardt 1916, Gigon 1935, Kirk 1954, Marcovich 1967, Kahn 1979) are abbreviated to the author’s surname, enclosed in parentheses: for example, ‘(Kahn),’ ‘(Marcovichad loc).’ Full titles of such works can be found in the bibliography, pp 203–6. References to other critical studies are also abbreviated to the author’s surname, but the specific page number is then cited; when more than one work by an author is listed in the bibliography, the individual items are identified by the date of publication. Pre-Socratic...

This section contains a translation of all thetestimoniaconcerning Heraclitus printed in D-K (139ff) except numbers 2, 3b, and 14a; the numbering system and the order of thetestimoniain D-K has also been followed. Subdivisions within atestimoniumreflect standard editorial practice for the author in question. The symbol [ ] indicates the immediate context of thetestimonium; 〈 〉 indicates what seems to be a natural addition in English to make sense of the Greek text; ( ) indicates an explanatory comment or query by the translator; and † … † or † indicates the presence of...

An account of Heraclitus can reasonably begin with his views on the nature of knowledge. Is knowledge possible, and, if so, under what circumstances and to what extent? The question had been posed earlier by Xenophanes (fragment 34), and the response had been a pessimistic one: ‘no one knows, or will ever know, the clear truth about the gods and about everything I speak of; for even if one chanced to say what was completely true, one does not oneselfknowthis (ie, that itiscompletely true, TMR). Seeming, rather, is wrought over all things.’ For Heraclitus, by contrast,...