The Church disagrees with you. Augustine and Aquinas had no problem finding the devil in Isaiah 14:12 as I noted already in post #6. I will add to that this clear explanation from the
Catholic Encyclopedia:
This interpretation is most economically reiterated in Bishop Challoner’s note for the verse in his revision to the Douay-Rheims bible:
1. Isa. 14 does not refer to the devil, even so - it** can** be applied to the devil - as happens in Luke 10 & Rev. 12 but that is not is same as saying that the literal meaning includes a reference to the devil; or that, because those NT passages refer to what Isa says, they mean what Isaiah meant. A simple illustration - people often use Biblical phrases in every day speech, because the Bible has influenced everyday speech - that they iuse words from the Bible, is no reason to take for granted that they always intend to mean what the quoted words meant in their original context.
Isaiah 7.14 is a direct quotation from another Canaanite myth - the words are identical: does every reader who quotes the verse, intend to refer to the myth, rather than to Christ or to Hezekiah (who is probably referred to in Isaiah’s use of the words) ? Surely not. If words can never be re-applied to mean what originally they did not mean, then we cannot even speak of Christ Himself, because “anointed”, like “Saviour”, or “Lord” would then have to mean what it meant before being referred to Him.
The passages later than Isaiah 14, are
re-applying it - not
saying what it means. Jesus & John & Luke are not saying what Isa. 14 means, but applying its phrases & ideas to their own situations.
The literal meaning has to be found, if the text is to be interpreted correctly - as St.Thomas points out. Neither he nor Jerome had any means of knowing about Canaanite myths, Helel, Shachar, etc; nor did the authors of the Cath.Enc. - for the very good reason that those three sources are from a time between the loss of the Ugaritic texts & myths, & their re-discovery. Bishop Challoner could not say anything about Ugarit, for the same reasons. One cannot be expected to take account of texts of which nothing is known in one’s own time. For scholars since the discovery of those texts, OTOH, the case is different - they do know of them, they can read them, they can compare them with other info from the OT’s world - so they do. To ignore those texts, would be wrong. No responsible interpreter can ignore evidence - whether this agrees with previous, less well-informed, interpretations, or not. Only a weak faith is threatened by archaeology or scholarship, or needs to ignore uncomfortable or puzzling details.
Satan is not referred to, or mentioned, in Isaiah 14, so it is irresponsible & immoral to say that the text refers to him, because it does not. If the older interpretation were followed, despite the evidence of its being wrong, such an interpreter would be telling a lie for the good of the Faith - than which there is very little that is more revoltingly immoral. Tradition has its place, but it if it leads men to lie, it has become devilish.
The text cannot be understood without knowledge of Hebrew - a language St. Thomas did not know. There is no virtue in sticking to mistaken interpretations of Isa. 14 - old or not, the interpretation that understands helel as Lucifer is simply wrong, regardless of the personal authority of the maker of the mistake - the text & its setting, not the interpreter, nor the age of the interpretation, is what is important.
To insist that a text must be interpreted from its translated form, even if this ignores its meaning in the original language, makes no sense. The Declaration of Independence should not be interpreted as though it had been written in 20th-century German, & been influenced by Marxist political theory - no student of politics would be so stupid, & no lecturer would tolerate such stupidity. Yet that is what people are being asked to do, if they must not go back to what Isaiah said & meant in his own language & setting.
The Church managed to accommodate the rediscovery of Mesopotamian texts into its tradition of inyterpreting the Bible. It has also done the same with the discoveries at Ugarit. So it is ill-informed, as well as out-dated, to rely on the CE as though only the intepretations known when the CE was published - in 1913-22 IIRC, if so late - were allowed. That is simply not the case - there is no more reason to take the CE as the last word on Biblical interpretation, than there is to assume that because manned space flight was unknown in 1922, it therefore unknown in our time, in 2007.