Bulfinch's Mythology (The Age of Fable - The Age of Chivalry - Legends of Charlemagne)

If no other knowledge deserves to be called useful but that which helps to enlarge our possessions or to raise our station in society, then Mythology has no claim to the appellation. But if that which tends to make us happier and better can be called useful, then we claim that epithet for our subject. For Mythology is the handmaid of literature; and literature is one of the best allies of virtue and promoters of happiness. 
Without a knowledge of mythology much of the elegant literature of our own language cannot be understood and appreciated. When Byron calls Rome "the Niobe of nations," or says of Venice, "She looks a Sea-Cybele fresh from ocean," he calls up to the mind of one familiar with our subject, illustrations more vivid and striking than the pencil could furnish, but which are lost to the reader ignorant of mythology. Milton abounds in similar allusions. The short poem "Comus" contains more than thirty such, and the ode "On the Morning of the Nativity" half as many. Through "Paradise Lost" they are scattered profusely. This is one reason why we often hear persons by no means illiterate say that they cannot enjoy Milton. But were these persons to add to their more solid acquirements the easy learning of this little volume, much of the poetry of Milton which has appeared to them "harsh and crabbed" would be found "musical as is Apollo's lute." Our citations, taken from more than twenty-five poets, from Spenser to Longfellow, will show how general has been the practice of borrowing illustrations from mythology. 
The prose writers also avail themselves of the same source of elegant and suggestive illustration. One can hardly take up a number of the "Edinburgh" or "Quarterly Review" without meeting with instances. In Macaulay's article on Milton there are twenty such. 
But how is mythology to be taught to one who does not learn it through the medium of the languages of Greece and Rome? To devote study to a species of learning which relates wholly to false marvels and obsolete faiths is not to be expected of the general reader in a practical age like this. The time even of the young is claimed by so many sciences of facts and things that little can be spared for set treatises on a science of mere fancy...