Tale consists simply in the narration of a story
either founded on facts, or created solely by the imagination, and
not necessarily associated with the teaching of any moral lesson. The
Parable is the designed use of language purposely intended to convey
a hidden and secret meaning other than that contained in the words
themselves; and which may or may not bear a special reference to the
hearer, or reader. The Fable partly agrees with, and partly differs
from both of these. It will contain, like the Tale, a short but real
narrative; it will seek, like the Parable, to convey a hidden meaning,
and that not so much by the use of language, as by the skilful
introduction of fictitious characters; and yet unlike to either Tale
or Parable, it will ever keep in view, as its high prerogative, and
inseparable attribute, the great purpose of instruction, and will
necessarily seek to inculcate some moral maxim, social duty, or
political truth. The true Fable, if it rise to its high requirements,
ever aims at one great end and purpose representation of human motive,
and the improvement of human conduct, and yet it so conceals its design
under the disguise of fictitious characters, by clothing with speech the
animals of the field, the birds of the air, the trees of the wood, or
the beasts of the forest, that the reader shall receive advice without
perceiving the presence of the adviser. Thus the superiority of the
counsellor, which often renders counsel unpalatable, is kept out of
view, and the lesson comes with the greater acceptance when the reader
is led, unconsciously to himself, to have his sympathies enlisted in
behalf of what is pure, honorable, and praiseworthy, and to have his
indignation excited against what is low, ignoble, and unworthy. The true
fabulist, therefore, discharges a most important function. He is neither
a narrator, nor an allegorist. He is a great teacher, a corrector of
morals, a censor of vice, and a commender of virtue. In this consists
the superiority of the Fable over the Tale or the Parable. The
fabulist is to create a laugh, but yet, under a merry guise, to convey
instruction. Phaedrus, the great imitator of Aesop, plainly indicates
this double purpose to be the true office of the writer of fables.

Duplex libelli dos est: quod risum movet,
Et quod prudenti vitam consilio monet.

The continual observance of this twofold aim creates the charm, and
accounts for the universal favor, of the fab