Break a butterfly on a wheel

Use disproportionate force to achieve an objective and though rarely used these days it became a popular expression from the mid-18th century onwards. The wheel here is the breaking wheel, a gruesome medieval instrument of capital punishment where the condemned was literally broken on the wheel by levering an iron bar through the spokes of the wheel to break the limbs. Alexander Pope in Epistle to Dr. Arbuthnot (1735) wrote the rhetorical question, “Who breaks the butterfly on the wheel?” In other words, who would use such force on a delicate creature like a butterfly? Pope’s image of breaking a butterfly on the wheel struck a powerful chord, hence the expression.