Premise:  the sculpture of Two Slaves by Michelangelo; Leonardo da Vinci's Mona Lisa (La Joconde) and Virgin of the Rocks; Titian's voluptuous Woman at Her Toilet and somber Entombment of Christ; the poignant Old Man and His Grandson of Ghirlandaio.
Hypothesis: Da Vinci's Virgin of the Rocks is also known as the Madonna of the Rocks.
Label: neutral