Edgar Huntly by Charles Brockden Brown — Read

Mrs. Lorimer had a twin-brother. Nature had impressed the same image upon them, and had modelled them after the same pattern. The resemblance between them was exact to a degree almost incredible. In infancy and childhood they were perpetually liable to be mistaken for each other. As they grew up, nothing, to a superficial examination, appeared to distinguish them, but the sexual characteristics. A sagacious observer would, doubtless, have noted the most essential differences. In all those modifications of the features which are produced by habits and sentiments, no two persons were less alike. Nature seemed to have intended them as examples of the futility of those theories which ascribe every thing to conformation and instinct and nothing to external circumstances; in what different modes the same materials may be fashioned, and to what different purposes the same materials may be applied.

Perhaps the rudiments of their intellectual character, as well as of their form, were the same; but the powers that in one case were exerted in the cause of virtue were, in the other, misapplied to sordid and flagitious purposes.