Lewis & Short

perspĭcācĭtas, ātis, f. [perspicax], sharp-sightedness, discernment, discrimination: qui nullā perspicacitate, sine innocentium sontiumque differentiā, … damnarunt, Amm. 15, 3, 2; cf.: perspicacitas, τὸ συνοπτικόν, Gloss. Lab.