Answer by Bryant Kirkland
This is a good question, and I will scrape only the tip of the iceberg here in saying that Plutarch’s problems with Herodotus have a lot to do with Plutarch’s ideas about representation, both of one’s character and of historical events as represented in writing. From Plutarch’s perspective, Herodotus has gotten away with murdering the facts, as it were, and Plutarch wants to convict him not only of his intellectual crimes but also of the malicious intent that motivated them.
The relevant text for thinking about this question is Plutarch’s On the Malice of Herodotus (de malignitate Herodoti), likely written in Plutarch’s later years when he was preparing to write the Parallel Lives and reading a lot of Herodotus. Plutarch writes in the opening sections that he is setting out to defend ‘our ancestors and the truth’ from what he calls Herodotus’s ‘malice’. This word translates the Greek term kakoêtheia, whose component parts could be more literally translated as ‘bad character’ or ‘ill temperament’. That bit about the ancestors is important, too. As many scholars have noted, Plutarch has decidedly patriotic interests in the treatise and spends a good amount of time critiquing Herodotus’s presentation of Thebes, near Plutarch’s place of birth. If you’re familiar with the Iliad’s Catalogue of Ships or the so-called Serpent Column that memorialized the city-states that resisted Persia, you’ll know that ancient Greeks (though of course not just ancient Greeks) were serious about proper acknowledgment of various places’ efforts in larger causes. Plutarch was no exception, and his belief that Herodotus improperly represented certain places must have been one motivating factor for his treatise. But that’s not all.
Plutarch in that opening section foregrounds the issue the really underlies his diatribe: Herodotus’ character (êthos). Plutarch would have us believe that Herodotus is a kind of literary con artist. The signature flaw of Herodotus’ Histories – the flaw that undergirds all of its errors – is that Herodotus is not who he poses to be: he seems like a good person who wants to tell the truth, but he is not. His mistakes are not innocent errors of fact or the product of bad research, but are instead purposeful distortions. And only a person of churlish and mean-spirited character would purposefully distort the truth or cast needless aspersion on others. Herodotus’ alluring writerly qualities therefore make his falsehoods, fabrications, omissions, and subtle acts of slander hard to detect, but all the same he can’t help, like some thief in hasty flight, leaving ‘traces’ or ‘footprints’ that allow us to spot his deceit, Plutarch says.
An example: according to Plutarch, Herodotus shows his bad character in his choosing to distort the truth under the guise of offering something accurate or laudatory. Plutarch complains at one point about Herodotus’s report (Hdt. 6.106.3-107.1) that the Spartans arrived late to Marathon because of a religious obligation to wait for the full moon before setting off on military campaign. Plutarch claims that this is not always true, and that Spartans did on other occasions march out before the full moon. Regardless of the accuracy of Plutarch’s claim, the essential point for him is that Herodotus suppresses evidence about the Spartans, thereby betraying his bias against them. A little later in the treatise Plutarch contends that Herodotus’ praise of Athens (7.139) does not really count as genuine praise, but rather ‘he praises the Athenians that he may speak ill of all the rest’, including of course Sparta. For Plutarch, Herodotus only attempts to conceal his biases behind explanatory statements (such as that about Spartan religion) or statements of apparent praise (when in fact he is dissing the rest of Greece, not really lauding Athens – a city that Herodotus anyway depicts inconsistently, per Plutarch). So the very mechanics of Herodotus’s historical composition, however ‘accurate’ they look, both conceal and (if you’re reading carefully) reveal Herodotus’s skulking bad spirit.
Now, you might still ask: isn’t history (ideally) about telling the truth? Isn’t Plutarch strait-jacketing Herodotus into offering an uplifting, ‘patriotic’ version of history? (And don’t think these visions of history have gone away: witness the proposals to teach ‘patriotic history’ in certain parts of the United States over the past few years especially.) Here one might recall Plutarch’s philosophical tendencies. He did not think that things that consisted of a fundamentally good essence should be represented in a bad way. As a comparison, consider how Plato (or Socrates) is worried about Homer’s representation of the gods. If the gods are good and just, is it right for Homer to represent them as petty and wilful? Similarly, if the Persian Wars did what many Greeks of Plutarch’s time wanted to think they did – kept Greece ‘free’, and brought different groups together in an act of resistance – then Herodotus has just too many ambiguities and opaque patches to be considered an accurate witness. To be sure, there is some circular thinking here, but in the end, Plutarch can convict Herodotus of being something of a failed artist who has cruelly painted ugly moles and zits on what Plutarch takes to be a clean complexion.
I encourage you to read the treatise for yourself and see what you think. And if you have access to an academic library, I recommend these helpful pieces of scholarship: John Marincola’s 1994 essay ‘Plutarch’s Refutation of Herodotus’ (in Ancient World 25.2: 191-203); Christopher Pelling’s 2007 chapter ‘De Malignitate Plutarchi: Plutarch, Herodotus, and the Persian Wars’ (in E. Bridges, E. Hall, and P.J. Rhodes (eds.) Cultural Responses to the Persian Wars, 472 BCE – 2003 CE. Oxford: 145-64); pages 9-34 especially of Emily Baragwanath’s Motivation and Narrative in Herodotus (Oxford 2008); and Geert Roskam’s 2017 essay ‘Discussing the past: Moral virtue, truth, and benevolence in Plutarch’s On the Malice of Herodotus’ (in A. Georgiadou and K. Oikonomopoulou (eds.) Space, Time and Language in Plutarch. Berlin: 161-74).