Maybe it's a reference to the idea that you need something more important than The Truth, so that you keep testing/refining your answer when you think you've got to the truth.

i'm going to reply to the quote as if it means "Truth doesn't have a moral valence" and rebuttal that truth should be held more sacred then morals rather then simply outside of it. For example if there are two cases and case 1 leads to a morally "better" (in quotes because the word better is really a black box) outcome then case 2 but case 1 leads to hiding the truth (including hiding from it yourself) then I would have to think very specifically about it. In short I abide by the rule "That which can be destroyed by the Truth should be" but am weary that this breaks down practically in many situations. So when presented with a scenario where i would be tempted to break this principle for the "greater good" or the "morally better case" I would think long and hard about whether it is a rationalization or that i did not expend the mental effort to come up with a better third alternative.