Someone who is clear and understands things shows perspicuity. When it comes to particle physics, it helps to have a teacher of real perspicuity to explain its complex principles.
It takes real perspicuity to unravel the mysteries of Cher's enduring career. Pop stars usually burn out in a matter of years, so explaining how she's managed to survive for decades is not easy: The many twists and turns of her career are almost impossible to track unless you're an observer of genuine perspicuity. By all rights, she should have been washed up twenty years ago, but a person who displays a deep knowledge of her special genius can explain how she's done it. They've got amazing perspicuity.