Here Mr. Micawber quotes from the play Cato (1712) by Joseph Addison (1672-1719).
It must be so,—Plato, thou reasonest well!
Else whence this pleasing hope, this fond desire,
This longing after immortality?
Or whence this secret dread and inward horror
Of falling into naught? Why shrinks the soul
Back on herself, and startles at destruction?
’T is the divinity that stirs within us;
’T is Heaven itself that points out an hereafter,
And intimates eternity to man.
Eternity! thou pleasing, dreadful thought!
Cato Act V: Scene 1