There doesn't seem to be an English word describing the ability to tell truth from a lie. I've Googled, and posted on my FB account, but can't seem to find a word that precisely describes this ability.

• Discernment. M-W defines this as "able to see and understand people things, or situations clearly and intelligently." Best so far, but a bit off the mark.
• The antonym of gullible
• A discerning ear
• (Slang) anti-bs meter; able to discern bullsh!t.

Others have suggested guarded, prudent, realistic, astute, and perceptive... but none of these precisely describe the quality that I've described.

I don't think that English has a word to describe this! Perhaps something from Latin, Hebrew, or another language?

Tyvm Keith :^)