Laudator Temporis Acti

Donald Kagan, The Outbreak of the Peloponnesian War (Ithaca: Cornell University Press, 1969; rpt. 1989), p. 378, discussing the historicity of the Spartan Assembly in 475, reported only by Diodorus Siculus 11.50, whose source is presumed to be Ephorus:

With what I hope is the higher naiveté of this century, I believe in the conference, the decisive presence of Hetoemaridas, the general tenor of his remarks, and even in the accurate recollection of his words by the Spartan source of Ephorus. There is no doubt that Ephorus knew many true things that neither Herodotus nor Thucydides reports. In this period, which falls outside the main interest of both historians, the argument from silence is worthless. It is bad method to ignore the report of an ancient author that is not contradicted by another source, internally impossible, or self-contradictory. Thus, there is no reason to doubt the conference.

The phrase "the higher naiveté" mocks the pretensions of "the higher criticism." In Kagan's Open Yale Course CLCV 205: Introduction to Ancient Greek History, Lecture 3: The Dark Ages, Lecture Chapter 1, he elaborates on his point of view:

And so there is this critical school that says, "I won't believe anything unless it is proven to me." At the other extreme, there's me, the most gullible historian imaginable. My principle is this. I believe anything written in ancient Latin or Greek unless I can't. Now, things that prevent me from believing what I read are that they are internally contradictory, or what they say is impossible, or different ones contradict each other and they can't both be right. So, in those cases I abandon the ancient evidence. Otherwise, you've got to convince me that they’re not true.

Now, you might think of this as, indeed, gullible. A former colleague of mine put the thing very, very well. He spoke about, and I like to claim this approach, the position of scholarship which we call the higher naiveté. The way this works is, you start out, you don't know anything, and you're naïve. You believe everything. Next, you get a college education and you don't believe anything, and then you reach the level of wisdom, the higher naiveté, and you know what to believe even though you can't prove it. Okay, be warned; I'm a practitioner of the higher naiveté. So, I think the way to deal with legends is to regard them as different from essentially sophisticated historical statements, but as possibly deriving from facts, which have obviously been distorted and misunderstood, misused and so on. But it would be reckless, it seems to me, to just put them aside and not ask yourself the question, "Can there be something believable at the root of this?"

Kagan's "former colleague" may be Peter Gay (1923-2015), who used the phrase "the higher naiveté" in "Rhetoric and Politics in the French Revolution," American Historical Review 66.3 (April, 1961) 664-676 (at 676).