The origin of Poetry is ascribed to that age which succeeded the creation of the world: and as the keeping of flocks seems to have been the first employment of mankind, the most ancient sort of poetry was probably pastoral. It is natural to imagine, that the leisure of those ancient shepherds admitting and inviting some diversion, none was so proper to that solitary and sedentary life as singing; and that in their songs they took occasion to celebrate their own felicity. From hence a poem was invented, and afterwards improved to a perfect image of that happy time; which, by giving us an esteem for the virtues of a former age, might recommend them to the present. And since the life of shepherds was attended with more tranquillity than any other rural employment, the poets chose to introduce their persons, from whom it received the name of Pastoral.
A Pastoral is an imitation of the action of a shepherd, or one considered under that character. The form of this imitation is dramatic, or narrative, or mixed of both: the fable simple, the manners not too polite nor too rustic: the thoughts are plain, yet admit a little quickness and passion, but that short and flowing: the expression humble, yet as pure as the language will afford; neat, but not florid; easy, and yet lively. In short, the fable, manners, thoughts, and expressions are full of the greatest simplicity in nature.
The complete character of this poem consists in simplicity, brevity, and delicacy; the two first of which render an eclogue natural, and the last delightful.