"Reader! — You have been bred in a land abounding with men, able in arts, learning, and knowledges manifold, this man in one, this in another, few in many, none in all. But there is one art, of which every man should be'master, the art of reflection. If you are not a thinking man, to what purpose are you a man at all? In like manner, there is one knowledge, which it is every man's interest and duty to acquire, namely, self-knowledge: or to what end was man alone, of all animals, endued by the Creator with the faculty of self-consciousness?"