Subtlety

Part of speech: noun (n.)

1. The quality or state of being subtle, or sly; cunning; craftiness; artfulness. The fox which lives by subtlety. Shak.

2. Nice discernment with delicacy of mental action; nicety of discrimination.

3. Something that is sly, crafty, or delusive. Unlearned in the world's false subtleties. Shak.