Adams, Barry B. "The Prudence of Prince Escalus."
English Literary History 35 (1968): 32-50.

Thesis: The author's thesis is stated most clearly in the last paragraph of his essay:

Considered simply as a character within the play world he [Prince Escalus] is a model of prudence, clearly superior to the other characters in this respect. But although he comes closer than the others to the providential view of affairs, even he fails, precisely because his knowledge of events is incomplete. His rationality is therefore unable to "destroy" the power of fortune, and as a result events fall out in ways unintended or unexpected -- that is, they happen by "chance" or "accident" in the strict sense of these terms. But the Prince is more than a character within the play world. He is also the emblem of prudence, and his "failure" in this capacity is an index of Shakespeare's artistic success. The very instability of a symbolic figure in which prudence merges with fortune epitomizes Shakespeare's purpose in Romeo and Juliet. In this view of the play, the underlying tragic conception as embodied in the bifrontal Prince -- the character who mediates between play world and audience -- turns out to be more sophisticated and profound than most critics have been willing to admit. For Shakespeare is in this play fundamentally concerned with the tragic limitations of man's most ennobling faculty, his "god-like reason" -- a faculty which, forced to operate in time and always endangered by ignorance, produces effects virtually indistinguishable from those commonly attributed to the blind, two-faced Fortuna.    (50)
The rest of the essay is largely concerned with establishing that Prince Escalus is indeed an emblem of Prudence. This is done by drawing parallels between Escalus and emblems (pictures and literary personifications) of Prudence.

Bottom Line: OK, but a lot to wade through.