In the quote from Cormac McCarthy's "No Country for Old Men," the author reflects on the enduring nature of truth amidst deception. He suggests that, despite the prevalence of lies, the ultimate truth remains constant and unchanging, much like a substance that cannot be altered. This idea highlights the resilience of truth, suggesting that even while falsehoods may rise and fall, truth will always remain steadfast.

Furthermore, McCarthy illustrates a sense of inevitability regarding truth. Just as salt cannot be salted further, the essence of truth cannot be tainted or corrupted. This underscores the philosophical notion that truth is an objective reality that exists independently of human manipulation, a point that resonates throughout the narrative of the book.