Robert Silverberg's Lord Valentine's Castle is not as good a book as I had thought when I was 16. It's rags-to-riches, amnesia-to-ambrosia, throne-reclaiming plot is a little too adolescent wish-fulfilment for my taste these days. The love interest is something of a cypher, which back then would have counted in its favour too, but nowadays rather less so. And we have the usual SF/fantasy conflation of species with characterisation.
That said, it's aged rather better than its publication in '79 than might be expected. Part of the reason for it is that LVC is a massive, heartfelt homage to the 20's and 30's planetary romances of Edgar Rice Burroughs and his pulp comrades. As such, Silverberg's world building is chock-full of old wierd tropes - colourful aliens with colourful names and psychic powers, half-understood ancient technologies and epic architectural follies.
He also gives square-jawed science fantasy something of a 70's makeover. Valentine, the protagonist, is John Carter by way of Donovan, a gentle soul disinclined to violence, reluctant to abandon his Good Life as a travelling juggler to do the right thing, man. Although his Hamlet moment is mercifully brief, that it happens at all is a mark of the dropout decade.
The besetting sin of Silveberg's world is colonisation and the driving of the indigenous race into reservations - a theme amplified in the sequel Valentine Pontifex and again a direct challenge to the unabashed jingoism of the pulps.
Whether Valentine succesfully checks his privilege over the course of the two books is a question I prefer to leave open - it very much depends on how easy you find liberal reconciliation to swallow. What this Aquarian take on science-fantasy certainly achieves is that rare thing in the genre - a set of villains whose motivations are entirely reasonable even if their means are deplorable.
And that, utlimately, is the achievement of Lord Valentine's Castle: revisionist pulp SF which introduces a (slightly) greater moral complexity and attempts to address the genre's hypermasculinity and White Spaceman's Burden, while still retaining the joie de vivre and exoticism of its predecessors.