It is not very easy to find an action or event that can be efficaciously represented by a painter.

He must have an action not successive but instantaneous; for the time of a picture is a single moment.  For this reason, the death of Hercules cannot well be painted, though, at the first view, it flatters the imagination with very glittering ideas:  the gloomy mountain, overhanging the sea, and covered with trees, some bending to the wind, and some torn from their roots by the raging hero; the violence with which he rends from his shoulders the envenomed garment; the propriety with which his muscular nakedness may be displayed; the death of Lycas whirled from the promontory; the gigantick presence of Philoctetes; the blaze of the fatal pile, which the deities behold with grief and terrour from the sky.

All these images fill the mind, but will not compose a picture, because they cannot be united in a single moment[2].  Hercules must have rent his flesh at one time, and tossed Lycas into the air at another; he must first tear up the trees, and then lie down upon the pile.

The action must be circumstantial and distinct.  There is a passage in the Iliad which cannot be read without strong emotions.  A Trojan prince, seized by Achilles in the battle, falls at his feet, and in moving terms supplicates for life.  “How can a wretch like thee,” says the haughty Greek, “intreat to live, when thou knowest that the time must come when Achilles is to die?” This cannot be painted, because no peculiarity of attitude or disposition can so supply the place of language as to impress the sentiment.

The event painted must be such as excites passion, and different passions in the several actors, or a tumult of contending passions in the chief.

Perhaps the discovery of Ulysses by his nurse is of this kind.  The surprise of the nurse mingled with joy; that of Ulysses checked by prudence, and clouded by solicitude; and the distinctness of the action by which the scar is found; all concur to complete the subject.  But the picture, having only two figures, will want variety.

A much nobler assemblage may be furnished by the death of Epaminondas.  The mixture of gladness and grief in the face of the messenger who brings his dying general an account of the victory; the various passions of the attendants; the sublimity of composure in the hero, while the dart is by his own command drawn from his side, and the faint gleam of satisfaction that diffuses itself over the languor of death; are worthy of that pencil which yet I do not wish to see employed upon them.

If the design were not too multifarious and extensive, I should wish that our painters would attempt the dissolution of the parliament by Cromwell[3].  The point of time may be chosen when Cromwell, looking round the Pandaemonium with contempt, ordered the bauble to be taken away; and Harrison laid hands on the Speaker to drag him from the chair.