We all know what was written on the surface of the One Ring—visible when the metal was heated, as it had been upon Mairon the smith's hand.
Ash nazg durbatulûk, ash nazg gimbatul,
ash nazg thrakatulûk, agh burzum-ishi krimpatul.
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them.
However, it occurred to me that the claims of this verse are not entirely accurate. The One Ring gave Sauron the power to rule the other rings and their wearers. For the sixteen rings that he himself had helped create, his power over them remained even after he lost the One.
However, the other parts of the verse seemed to be more "aspirational" than real. In particular, the One Ring did not give him the ability to find the Three, which he had never touched. As long as they were inactive, he was never able to locate them. He thus could not gather them to himself the way he did the others.
Did Tolkien ever comment on this question, in his essays or letters? Was it merely a matter of the Dark Lord's hubris, thinking that he would be able to master all the Great Rings, including the Three, and bring them under his dominion? Or did the question pass unnoticed?