One of The Six Stats, abbreviated as WIS.
This is the stat that determines perceptiveness in general, but also affects the ability to understand complicated moral quandaries and make sound judgments free from personal bias, possibly informed by experience. The ability to understand divine revelations or connect to forces of nature is also often attributed to Wisdom, as is the ability to understand the trappings of a setting (possibly including the fourth wall).
To put it in other terms, The Philosopher will always have remarkably high wisdom, independent of what his other stats might be, a Book Dumb character usually has decent wisdom, but average to below average intelligence, while a Ditzy Genius will have high intelligence, but remarkably low wisdom.
Amusingly, in most Dungeons & Dragons systems, spot and listen/perception checks tends to be tied to Wisdom, and the older a character is in these systems the more wisdom they will have by default. Ergo: the older a character is, the better they are at hearing and seeing things.
Of the six stats, Wisdom's association with the divine, willpower and simple sensible judgment make it the most traditionally heroic stat. Villains with high Wisdom tend to be pragmatic, if not in it for a greater cause.
12-15: The little things such as finding missing socks and completing word searches are performed with proficiency. This stage indicates sharp senses, but not to the scale of, say, eagle vision.
16-19: A watchman or doctor is a likely occupation — this character has become attuned to the consequences of their actions well enough to see past their own good (unless, of course, their alignment dictates villainy).
20-23: The character sees like a hawk, can track trails like a bloodhound and speaks fluent divine - they can understand things beyond the realms of lesser consciousness.
24+: The character has graduated with honors from the Multiversal School of Hard Knocks. They can see the cosmos unfold in every little detail, persevere through the worst psychological torture conceivable and come out with a philosopher's outlook. Sagely is an understatement.