The purpose of playing, whose end, both at the first and now, was and is, to hold as 'twere the mirror up to nature: to show virtue her feature, scorn her own image, and the very age and body of the time his form and pressure.
William Shakespeare (1564–1616), British dramatist, poet. Hamlet, in Hamlet, act 3, sc. 2, l. 20-4.
Hamlet's advice to the actors has its origins in classical rhetoric; they are to show plainly the appearance (feature) of virtue and of vice, and reflect the present state of affairs; "pressure" means impression, as if in wax.