One passage in particular, however, really threw me when I ran across it earlier today, for the sheer oddity of what Lewis was saying. He's talking about Wms' poem "Taliessin in the Rose-Garden", from Wms' second* book in the Taliessin cycle, THE REGION OF THE SUMMER STARS . In the context of explaining references to the Fisher King, the Red Spot on Jupiter, and all the women of the Empire, Lewis writes
Williams assumes** that the huge reddish spot which astronomers observe on the surface of Jupiter is a wound and the redness is that of blood. Jupiter, the planet of Kingship, thus wounded, becomes, like the wounded King Pelles, another ectype of the Divine King*** wounded on Calvary. And finally we have one of those physiological symbols which will seem grotesque to many readers but which spring inevitably from the poet's whole view of the body and are meant with all seriousness. The menstrual flow in women presents certain problems on the scientific level in so far as it is not really quite paralleled by what seem at first to be the parallel phenomena in the females of other species. Williams sees it as a 'covenant in the flesh'. By it all women naturally share in the great sacrifice. That, indeed, is why they are excluded from the priesthood; excluded from the office because they thus share mystically in the role of the Victim;
Well are women warned from serving the altar
who, by the nature of their creature, from Caucasia to Carbonek,
share with the Sacrifice the victimization of blood.****
So far as I can tell, the bit about "certain problems on the scientific level" is Lewis's intrusion and doesn't represent anything Wms wrote. On the other hand, occasionally Lewis draws on conversations he had with Wms to elucidate passages in the poems, though generally he identifies his source. In any case, I have no idea what science or pseudo-science Lewis is referring to here.
The idea that women's having periods disqualifies them from the priesthood is a much, much older excuse and does indeed seem to genuinely represent Wms' thought, though it turns out he had an unusual take on this (as on practically everything else). The primitive idea (cf. the Old Testament) is that this makes them 'unclean' in some way. But saying 'Moses thinks girls have cooties' isn't much of a reasoned argument for excluding women. For his part, Lewis in his essay "Priestesses in the Church" -- which I once dubbed his single worst essay -- falls back on cliches about masculine and feminine principles representing eternal verities as his justification for proclaiming that only Men can serve as Priests.
Wms turns this around completely: in an argument diametrically opposed to that in Lewis's essay, he identifies all women with Christ himself because both bleed ("all women . . . share mystically in the role of the Victim"). I confess I don't understand how this is supposed to sync up with the doctrine that the priest stands in for Christ during the mass, assuming Wms believed that. Perhaps "mystically" is a code word meaning that what he's saying can't be translated into rational terms. In any case, I find it interesting that when Lewis came to write his own essay on the topic, the same year that WILLIAMS AND THE ARTHURIAD was published, he completely ignored Wms' ideas and entirely went his own way.
In any case, for anyone thinking of reading Wms' poems, I'd advise just plunging right in at the beginning and reading both volumes straight through. Like Pound's Cantos, you're supposed to enjoy the word-music and flow of ideas and images first and can go look up all the references and try to make sense of it later. Anyone who's read Yeats and Pound and Eliot will find that Wms, while no Frost, isn't nearly as stiff going as reputation wd have it.***** Wms isn't one of the greats -- there's a reason he never made it into the canon or onto the syllabus -- and as an attempt to retell the Arthurian legend it's a mess (all Wms is really interested in is the Grail; he isn't interested in Arthur himself at all). But if he's a minor poet, his poetry is still distinctive and worth reading, esp. if you want to see just how far through the looking-glass an Inkling cd go.
*actually his third, but most people ignore HEROES AND KINGS  which, given some of the surprises contained therein is a good thing for Wms' reputation.
**I wd have said, 'adopts the conceit that'
****p. 334 in the Eerdmans omnibus edition I have, a gift from Kath Filmer, which prints TALIESSIN THROUGH LOGRES, THE REGION OF THE SUMMER STARS, and ARTHURIAN TORSO with continuous pagination. The three lines at the end quoted from Wms' poem appear on page 144.
*****one final shortcoming of Lewis's commentary worth noting is that while he does admit to (and lament) one poem's showing T. S. Eliot's influence, he nowhere credits Yeats as the source of Wms' central image, Byzantium as a symbol of Order in a changing word (e.g., "Sailing to Byzantium" ).