THIS MIGHT SURPRISE YOU
The answer
The handwritten copies, to recover the earliest wording. Lower criticism is now called textual criticism. Higher criticism asked where a book came from: who wrote it, when, and from what.
Why it’s interesting
A verse like Deuteronomy 32:8, where copies read "gods" or "the Israelites," is textual criticism's ground. Two books listing the same wrongs in nearly the same words, like 2 Kings 21 and 2 Chronicles 33, are the higher kind's.
Scholarly consensus
Learn the Bible.
Not just the stories, but the history, authorship, and scholarship behind it.