Fuseli and Blake, self-taught artists strongly influenced by their religious upbringing, found their subjects in the works of Milton and Shakespeare, who were then being rediscovered. Both authors endowed the champions of evil (e.g. Milton's Satan, rebellious Prince of Darkness) with a strange and powerful beauty, while figures like Shakespeare's witches in Macbeth tapped into popular superstition.
Cowper, like Shakespeare, inspired the painters of Dark Romanticism by showing how reason could collapse, in a manner simultaneously comic and tragic, and misfortune or temptation tip the individual into madness. Fuseli's Mad Kate and The Three Witches are compelling images of madness, lust for power and the sudden irruption of suppressed urges – elements which he later used in subjects of his own devising, like The Nightmare.
Painters also used the Sublime – an aesthetic concept introduced by Edmund Burke – to elicit a strong emotional response. Beauty flatters sense and gratifies reason, but the Sublime overwhelms and transcends them, inspiring awe and wonder. Thus the "sublime" landscapes of John Martin and Samuel Colman powerfully convey the huge energy and elemental fury of natural forces unleashed.
The adulterers Paolo and Francesca, Ugolino devouring his children, traitors condemned to tear one another to pieces – all are driven by imprisonment to commit acts contrary to nature.
The Romantic painters convey this sense of confinement by reducing the body to a naked, brutish beast, lighting it harshly and putting it full-centre in the picture – which weakens our human sympathy and makes us aware of our own dark impulses. Cannibalism is, with infanticide (Medea), one of their favourite "unnatural" acts – and deeply ambiguous.
Is its root motivation the desperate urge to survive, the frenzied desire to absorb and possess another's vitality or, in a new and literal sense, all-consuming hatred? It is also the unstated subject of Géricault's Raft of the Medusa – in effect, a floating prison which lifts Dante's Hell from the depths into the daylight. Collective damnation was another motif which fascinated these artists. Looking at the convulsed and spiraling bodies in Boulanger's Witches' Sabbath, the viewer does not know whether this is orgy or massacre, drunken riot or black mass – and even unbelievers feel the picture's power.