I am grateful for two recent blog posts (here and here) by LDS biblical scholar David Bokovoy about the issue of authorship of the book of Isaiah. In these blog posts, Dr. Bokovoy describes the evidence supporting the scholarly consensus that chapters 40–66 of the book of Isaiah were written after the Jewish exile into Babylon. This is of interest to Latter-day Saints because the Book of Mormon quotes Isaiah 48–54. If the scholarly consensus is correct, the quoted material would not have been available to Lehi’s family when they left Jerusalem.
This is not a new issue, but it is probably new to many Latter-day Saints (it is relatively new to me). Some members of the church may feel uneasy about this information. However, I believe it is important to keep in mind that the scholarly consensus about Isaiah is the honest result of capable people trying to explain the evidence to the best of their ability.
I have faith that the Book of Mormon is the “word of God.” As for what that means with respect to authorship of the book of Isaiah, I’m far less certain. While it is certainly possible that the scholarly consensus is incorrect, there does appear to be considerable evidence supporting post-exilic authorship of Isaiah 40-66. In any event, I believe that biblical scholars like Dr. Bokovoy are simply doing their best to honestly seek after the truth. Their efforts should be applauded, even when their conclusions make us uncomfortable. The words of Henry Eyring come to mind: “The fundamental principle that has guided my religious life is that I need believe only what is true. The gospel is the truth as learned or discovered by whatever means and tools I can lay my hand or mind on.”