Cunning

Definitions: (1) skillful; clever; shrewd; (2) created with dexterous proficiency; ingenious; (3) a display of keen insight; inventive; (4) pretty in a delicate way; cutely attractive

Synonyms: artful, astute, crafty, sly, subtle, wily

Quotes:
• Man has made many machines, complex and cunning, but which of them indeed rivals the workings of his heart? — Pablo Casals (1876-1973) Spanish cellist, composer, & conductor
• The tantalizing discomfort of perplexity is what inspires otherwise ordinary men and women to extraordinary feats of ingenuity and creativity; nothing quite focuses the mind like dissonant details awaiting harmonious resolution. — Brian Randolph Greene (1962-) American physicist & mathematician

Comment: Cunning also has the negative connotation of underhanded motives, but we are dealing with positive values here – and it is easy to tell the difference.