[QUOTE=Qadgop the Mercotan]
But the knowledge of the rings was not widely disseminated by the elves in the know. The three were dispersed among the most powerful Eldar, and not wielded. They didn’t talk much about the matter, as far as can be gleaned from JRRT’s writings. And while all this was going on, the men of the West lived in Numenor.
So Isildur could well have been expected to be ignorant regarding the matter of so much of Sauron’s power being tied up in his jewelry. He apparently knew just enough to cut the ring from Sauron, but beyond that?
Isildur had been widely respected in his lifetime. He rescued a fruit from the White Tree in the King’s Court in Numenor, right from under Sauron’s nose, thus preserving the tree for the Dunedain. He led a contingent of faithful away from the wreck of Numenor, and with his brother founded the realm of Gondor and Osgiliath, its chief city. He personally founded Minas Ithil in Ithilien.
So he was a pretty stand-up guy. While the ring could have seduced him, I still suspect he was mainly ignorant of its true nature.
[/QUOTE]
Isildur may not have understood the full potential of the Ring, true (but please note my response was to the concept posited that the elf-lords didn’t know what the Ring did
). But Elrond certainly knew what it did, and would have known that men had been swayed before by the rings that the Gift Giver had handed out. So I am certain he told Isildur sufficient when he urged him to toss the Ring into the fires of Orodruin to apprise Isildur of the Ring’s likely ability to corrupt any who might try to use it, or danger to the world if it remained around.
Personally, I’ve always considered Isildur a fore-runner of Boromir: fearless and proud, convinced in the rightness of what they do, destined to lead and knowing it. Contrast his sire, Elendil, who is much less all about himself: he leads because it’s his job and he happens to be good at it, but doesn’t really act all that proudly and self-enamoured about it. Isildur doesn’t destroy the Ring for two reasons. First, he thinks he deserves some recompense for losing his brother and father (among others), and isn’t likely to get any from the elves that remain after the battle. Second, he just doesn’t think it possible that he’d be unable to properly control and govern the Ring. He might even be correct, for look how quickly the Ring deserts him, which I think shows the Ring quickly sized him up as someone who would be difficult to control.
But I do not for a single minute think that Isildur took the Ring because he was ignorant of its potential.
ETA: And remember, there’s this silly piece of doggerel around talking about the whole thing:
Three rings for elven kings under the sky,
Seven for the dwarf lords in their halls of stone. etc. Not very enigmatic, that. 