It’s always something. First it was, “We have better evidence for Jesus than for the contemporary emperor Tiberius.” Matthew Ferguson annihilated that one. Then it was, “We have better evidence for Jesus than for Alexander the Great.” Which I annihilated in On the Historicity of Jesus (pp. 21-24). Or it was, “We have better evidence for Jesus than for Socrates.” Which I also annihilated in OHJ (Chapter 8.2, “The Socrates Analogy”). Or it was, “We have better evidence for Jesus than for Pontius Pilate, the guy who allegedly killed him.” Which I’ve also annihilated. And then it was, “We have better evidence for Jesus than for Julius Caesar.” Which I just annihilated. Now the claim going around is, “We have better evidence for Jesus than for Spartacus,” the enslaved gladiator of Thrace (now mostly Bulgaria) who led a nearly successful slave revolt against the Romans in Italy in 73-70 B.C.
Just like Julius Caesar (as I explained in my last post about this), and everyone else in these comparisons, when it comes to determining the probability of historicity, Spartacus differs from Jesus in two respects:
Spartacus belongs to a different reference class. He is not a worshiped deity whose only narratives are extensively mytho-fantastical. Spartacus does not belong to any myth-heavy reference classes at all (significantly sized sets of claimed historical persons most of whose members are mythical). Jesus does. See Chapter 6 of OHJ. I use the one significantly sized set we have for Jesus (high-scoring Rank-Raglan heroes: Element 48, Chapter 5.3), but Jesus actually belongs to several myth-heavy sets (worshiped deities, mystery-cult saviors, dying-and-rising demigods, culture heroes, heavenly founders: e.g. Elements 31, 36, 46, 47, Chapter 6.1-2, etc.). Spartacus belongs to not even one.
Spartacus actually belongs to a reference class of mundane military foes fighting a literate record-keeping nation’s armies, a class in which most members by far are historical. So we don’t even need more evidence to confirm he existed. We can trust it’s just very likely he did, because in such cases (in such sets of persons), every time we can check, it turns out it usually is the case that these people existed.
This is the first problem with trying to compare Jesus with ordinary people (OHJ, Chapter 6.2 and 6.5). Ordinary people are not usually mythical. There is little reason to have made them up or to have Euhemerized them (OHJ, Element 45). Ordinary people are not worshiped celestial gods with astonishing supernatural powers and suspiciously convenient names (Jesus means “Savior”), rapidly surrounded by wildly egregious myths, to serve as reified authorities for promoting certain cultural and religious norms. One must heed that distinction.
We have way better evidence for Spartacus anyway. There is a handy collection of literary sources online. But leading scholarship on the subject is Aldo Schiavone’s Spartacus (2013) and Brent Shaw’s Spartacus and the Slave Wars: A Brief History with Documents (2001).
It is typically claimed that our earliest references are Plutarch’s Life of Crassus (wr. c. 100 AD) and Appian’s Civil War (wr. c. 150 AD), which date hundreds of years after the fact (though they both used earlier sources). But that’s not at all true. Those are the earliest detailed narratives. And not the earliest written; the earliest that survive.
It is sometimes claimed that the oldest surviving historical source on Spartacus are some fragments of Livy (and his full account was in turn a major source for those later authors). Livy was born about ten years after the Spartacus war and wrote probably around the turn of the era, which makes Livy with respect to Spartacus comparable to Josephus with respect to Jesus. But there is a huge difference. We can tell even by extant summaries by his readers that Livy wrote extensively and believably about Spartacus (unlike anything in Josephus about Jesus) and had good and detailed information (unlike anything in Josephus about Jesus) and none of it shows signs of obvious forgery or meddling (unlike everything in Josephus about Jesus: OHJ, Chapter 8.9). So even just on this count, in Livy we already have better evidence for Spartacus than for Jesus. (We also have a poem of Horace, who was born around the same time as Livy, and wrote around the same time as Livy, also attesting to Spartacus, but only a brief and indeterminate line.)
But even that’s not the oldest thing we have. We also have fragments of Sallust’s Histories, which covered Spartacus (and was another major source used by later authors like Plutarch and Appian). Sallust was born about ten years before the Spartacus war, and by sharing the Senate with them would have known personally the persons who fought Spartacus (such as Crassus, but also Julius Caesar and Pompey, who were in the army at the time). And he wrote around 40 B.C., just thirty years after the Spartacus war, a better source than we have for Jesus in any form at all. This makes Sallust comparable to the letters of Paul, but unlike Sallust, Paul does not treat Jesus as a subject of narrative history or give any specific historical details about him or write anything biographical about him other than vague theological statements (OHJ, Chapter 11). So once again, in Sallust we have even better evidence for Spartacus than for Jesus.
And that’s just the earliest account we have pieces of. If we want just mentions attesting his historicity, then we are even better off than that. We have mentions of Spartacus from several of his contemporaries. We have him attested in the letters of Cicero: in Response to the Haruspices written in 57 B.C., just fourteen years after the Spartacus war (Cicero also mentions details of the Spartacus war albeit without naming Spartacus in Against Verres, written and orated to the Senate just three years after the war). Cicero was in his thirties and in the Senate and serving in Roman government during the Spartacus war. So he certainly would have known that the man and his war weren’t made up.
Spartacus is also attested in the Library of History by Diodorus Sicilus: fragment 39.22 mentions Spartacus, and reveals that Diodorus had written a whole section on the Spartacus war. Diodorus was a Greek, in his twenties during the war, and wrote his histories between 60 and 30 B.C., so a living contemporary historian writing about Spartacus earlier than anything we have for Jesus (apart from maybe the highly mythical Gospel of Mark: OHJ, Chapter 10.4). Which means Diodorus was also an available source for later authors. We also know the erudite Varro, who was in his forties during the Spartacus revolt and was thus in the Senate during the war, also attested to the existence and treatment of Spartacus. Because Varro’s books are quoted doing so by a later reader, Sosipater Charisius (a scholar of the 4th century A.D., his quotation of Varro is in Grammatical Arts 1.133). We have nothing at all like that for Jesus.
So, altogether, very much better than we have for Jesus.
But this is of course only in respect to establishing the bare fact of historicity. We don’t trust that all the surviving sources are wholly reliable in every detail. For example, Appian makes identifiable errors, and thus probably has made several unidentifiable ones as well (see the footnotes here, for example). Plutarch seems to have more reliably used Sallust and Livy and other sources. But there were also other historians of his same period who cover or mention Spartacus: Suetonius (c. 120 A.D.), Tacitus (c. 115 A.D.), Florus (c. 100 A.D.), Frontinus (c. 90 A.D.), and Paterculus (c. 20 A.D.). Possibly more. We don’t have this for Jesus: numerous objective historians researching his history from earlier sources and discussing it, all within one to two centuries after the event. (Even the one lone case, a single mention in Tacitus, cannot be traced to any source other than the Gospels, and probably was never really in Tacitus to begin with: OHJ, Chapter 8.10.)
We again use a prior probability here: historians in antiquity who used contemporary sources well, or were or knew contemporaries or witnesses, usually get major public facts correct, like the names of generals, the season and year of a campaign, etc., because there was good data for them to use on that (including public inscriptions), and they were held at least to minimal standards of reliability and fact-checking. Whereas the more gossipy or elusive stuff they often can’t be trusted on because they were prone to believing rumors or making them up, or treating inferences and conjectures as reported facts. This is true across the board. There is no historian in antiquity whose account of anything we trust entirely. There are just some historians we trust more than others, and more on some things than on others.
So there is plenty that is legendary or uncertain about Spartacus. And all scholars acknowledge this, and analyze the data in terms of probability and eyewitness or contemporary sourcing. But if all you want is to be assured of historicity, the evidence for Spartacus is way better than for Jesus.