Out of this nettle, danger, we pluck this flower, safety.

William Shakespeare (1564-1616): King Henry IV. Part I. Act ii. Sc. 3.

Tender-handed stroke a nettle,

And it stings you for your pains;

Grasp it like a man of mettle,

And it soft as silk remains.

'T is the same with common natures:

Use 'em kindly, they rebel;

But be rough as nutmeg-graters,

And the rogues obey you well.

Aaron Hill (1685-1750): Verses written on a window in Scotland.