Per·spi·cac·i·ty

Keenness of mental perception and understanding;

the ability to notice and comprehend what is not immediately obvious.

"Her perspicacity in analyzing complex legal cases made her one of the most sought-after attorneys in the city."

 From Latin perspicācitās (“sharpness of sight, discernment”), from perspicax (“sharp-sighted, acute”), from perspicere (“to look through, examine”).