To the terrible in nature are added portents of the supernatural, sudden violations of the uniformity of nature, the principle upon which all science is founded. The solitary bird of night has been seen in the crowded Capitol; fire has played around a human hand without destroying it; lions, forgetting their fierceness, have mingled with men; clouds drop fire instead of rain; graves are giving up their dead; the chance shapes of clouds take distinctness to suggest tumult on the earth. Such phenomena of nature and the supernatural, agitating from their appeal at once to fear and mystery, and associated by the fancy with the terrible in human events, have made a deep impression upon primitive thought; and the impression has descended by generations of inherited tradition until, whatever may be the attitude of the intellect to the phenomena themselves, their associations in the emotional nature are of agitation. They thus become appropriate as a Dramatic Background to an agitated passion in the scenes themselves, calling out the emotional effect by a vague sympathy, much as a musical note may set in vibration a distant string that is in unison with it.
This device then is used by Shakespeare in the second stage of the present play. We see the warning terrors through the eyes of men of the time, and their force is measured by the fact that they shake the cynical Casca into eloquence.
i. iii. 3.
Are not you moved, when all the sway of earth
Shakes like a thing unfirm? O Cicero,
I have seen tempests, when the scolding winds
Have rived the knotty oaks, and I have seen
The ambitious ocean swell and rage and foam,
To be exalted with the threatening clouds:
But never till to-night, never till now,