Max Muller was one of the greatest religious scholars of the 19th century. Born in Germany, he became fascinated with Eastern religion, and moved to England to be closer to the center of Indian scholarship in Europe. There he mastered English and Sanskrit alike to come out with the first English translation of the Rig Veda, the holiest book of Hinduism.
One of Muller's most controversial projects was his attempt to interpret all pagan mythologies as linked to one another, deriving from a common ur-mythology and ultimately from the celestial cycle. His tools were exhaustive knowledge of the myths of all European cultures combined with a belief in the interpretive power of linguistics.
What the significance of Orpheus' descent into the underworld to reclaim his wife's soul? The sun sets beneath the Earth each evening, and returns with renewed brightness. Why does Apollo love Daphne? Daphne is cognate with Sanskrit Dahana, the maiden of the dawn. The death of Hercules? It occurs after he's completed twelve labors (cf. twelve signs of zodiac) when he's travelling west (like the sun), he is killed by Deianeira (compare Sanskrit dasya-nari, a demon of darkness) and his body is cremated (fire = the sun). His followers extended the method to Jesus - who was clearly based on a lunar deity, since he spent three days dead and then returned to life, just as the new moon goes dark for three days and then reappears.
Muller's work was massively influential during his time, and many 19th century mythographers tried to critique his paradigm and poke holes in it. Some accused him of trying to destroy the mystery of religion, and others accused him of shoddy scholarship.
R.F. Littledale, an Anglican apologist, took a completely different route. He claimed that there was, in fact, no such person as Professor Max Muller, holder of the Taylorian Chair in Modern European Languages. All these stories about "Max Muller" were nothing but a thinly disguised solar myth.
Littledale begins his argument by noting Muller's heritage. He was supposedly born in Germany, only to travel to England when he came of age. This looks suspiciously like the classic Journey of the Sun, which is born in the east but travels to the west. Muller's origin in Germany is a clear reference to Germanus Apollo, one of the old appelations of the Greek sun god.
His Christian name must be related to Latin "maximus" or Sanskrit "maha", meaning great, a suitable description of the King of Gods, and his surname is cognate with Mjolnir, the mighty hammer of the sky god Thor. His claim to fame is bringing the ancient wisdom of the East to the people of the West - that is, illuminating them with eastern light.
Muller teaches at Oxford for the same reason that Genesis describes the sky as "the waters above" and the Egyptians gave Ra a solar barge: ancient people interpreted the sky as a river, and the sun as crossing that river upon his chariot (perhaps an ox-drawn chariot, fording the river?). His chair at Oxford is the throne of the sky, his status as Taylorian Professor because "he cuts away with his glittering shears the ragged edges of cloud; he allows the...cuttings from his workshop, to descend in fertilizing showers upon the earth."
I could go on; instead I recommend you read the original essay. The take-home lesson is that any technique powerful enough to prove that Hercules is a solar myth is also powerful enough to prove that anyone is a solar myth. Muller lacked the strength of a rationalist: the ability to be more confused by fiction than by reality. This makes the Hercules theory useless, but that is not immediately apparent on a first or even a second reading of Muller's work. When reading Muller's work, the primary impression one gets is "Wow, this man has gathered a lot of supporting evidence."
This is a problem encountered in many fields of scholarship, especially "comparative" anything. In comparative linguistics, for example, it's usually possible to make a case that two languages are related good enough to convince a layman, no matter which two languages or how distant they may be. In comparative religion, we get cases like this blog's recent discussion over the possible derivation of Esther and Mordechai defeating Haman from Ishtar and Marduk defeating Humbaba. The less said about comparative literature, the better, although I can't help but quote humor writer Dave Barry:
Suppose you are studying Moby-Dick. Anybody with any common sense would say that Moby-Dick is a big white whale, since the characters in the book refer to it as a big white whale roughly eleven thousand times. So in your paper, you say Moby-Dick is actually the Republic of Ireland. Your professor, who is sick to death of reading papers and never liked Moby-Dick anyway, will think you are enormously creative. If you can regularly come up with lunatic interpretations of simple stories, you should major in English.
The worst (but most fun to read!) are in pseudoscience, where plausible sounding comparisons can prove almost anything. Did you know the Mayans believed in a lost homeland called Atzlan, the Indonesians believed in a lost island called Atala, and the Greeks believed in a lost continent called Atlantis? Likewise, did you know that Nostradamus predicted a great battle involving Germany and "Hister", which sounds almost like "Hitler"?
Yet it would be a mistake to reject all such comparisons. In fact, I have thus far been enormously unfair to Professor Muller, whose work established several correspondences still viewed as valid today. Virtually all modern mythologists accept that the Hindu Varuna is the Greek Uranus, and that the Greek sky god Zeus equals the Hindu sky god Dyaus Pita and the Roman Jupiter (compare to Latin deus pater, meaning God the Father). Likewise, comparative linguists are quite certain that all modern European languages and Sanskrit derive from a common Indo-European root, and in my opinion even the Nostratic project - an ambitious attempt to link Semitic, Indo-European, Uralic. and a bunch of other languages - is at least worth consideration.
We need a test to distinguish between true and false correspondences. But the standard method, making and testing predictions, is useless here. A good mythologist already knows the stories of Varuna and Uranus. The chances of discovering a new fact that either confirms or overturns the Varuna-Uranus correspondence is not even worth considering.
Mark Rosenfelder has an excellent article on chance resemblances between languages which offers a semi-formal model for spotting dubious comparisons. But such precision may not be possible when comparing two deities.
I have what might be a general strategy for approaching this sort of problem, which I will present tomorrow. But how would you go about it?