Noah Webster
Sagacity
SAGAC'ITY, noun [Latin sagacitas.]
1. Quickness or acuteness of scent; applied to animals.
2. Quickness or acuteness of discernment or penetration; readiness of apprehension; the faculty of readily discerning and distinguishing ideas, and of separating truth from falsehood.
Sagacity finds out the intermediate ideas, to discover what connection there is in each link of the chain.