Discerner
From BiblePortal Wikipedia
King James Dictionary [1]
Discerner, n.
1. One who sees, discovers or distinguishes an observer. 2. One who knows and judges one who has the power of distinguishing.
He was a great observer and discerner of mens natures and humors.
3. That which distinguishes or that which causes to understand.
The word of God is quick and powerful--a discerner of the thoughts and intents of the heart. Hebrews 4 .
Webster's Dictionary [2]
(n.) One who, or that which, discerns, distinguishes, perceives, or judges; as, a discerner of truth, of right and wrong.