It is interesting to see Tolkien’s thought proceed, partly by deducing the hstory of the
palantíri from examining what he had previously written as though this were from genuine, independent sources and partly by new inventions.
Or are these new inventions? Some of Tolkien’s writing may have been destroyed or lost and some of Tolkien’s thoughts on details of his legendarium may have been quite clear in his mind but never written down previously.
Tolkien goes into great detail in this essay on the matter of the
palantíri needing to be oriented and into great detail on their polarization. But then in note 17 Christopher Tolkien remarks:
A later, detached note denies that the palantíri were polarized or oriented, but gives to further detail.
Possibly this change in Tolkien’s thought came about when Tolkien considered the unlikeliness of:
So it was ‘by chance’ as Men call it (as Gandalf would have said) that Peregrin, fumbling with the Stone, must have set it on the ground more or less ‘upright’, and sitting westward of it have had the fixed east-looking face in the proper position.
Removing the features of polarity and orientation avoids the element of chance.
Tolkien did however maintain, so far as is recorded, his belief that Gandalf was wrong, as originally pictured, in saying that Denethor did not presume to use the Stone until recently.
Tolkien indicates in this essay that Gandalf should be shown in the book to not say, “Denethor did not presume to use it” but rather “Denethor would not presume to use it”, making it clear that this is a surmise by Gandalf rather than a statement of fact, although not making clear that Tolkien thinks it an incorrect surmise. Christoper Tolkien indicates that “(apparently by mere oversight)” this change was not made with other changes introduced in the text of 1967. Only in the edition of 1994 was this change finally made.