Now surely in this motive of fear, thus remedied by exact ritual, we may trace a true civilizing element—the idea of Duty, Pietas, which as Cicero defined it, was ‘iustitia erga deos’: righteous dealing towards the gods, in expectation of righteous treatment on their part. And he would be a bold man who should assert that ‘iustitia erga deos’ had no effect in inducing the habit of ‘iustitia erga homines’: in other words that it could not react upon conduct. In the _pietas_ of the one typical Roman in literature both these elements are equally present. The _pietas_ of Aeneas is a sense of duty towards god and man alike; to his father, his son, and his people, as well as to the will of the gods, and to that solemn mission which is at once the religion of his life and the key to the great Roman poem[1512]. This is indeed that same sense of duty and responsibility which governed every Roman in authority in the best days of the State, whether paterfamilias, patronus, priest, or magistrate, and which was the motive power in the working of a constitution which lasted for centuries though only resting on a basis of trust. In this _pietas_, it is true, we find no sense of contrition for sin, no humbling of the individual self before an almighty Governor of the world; but we do find a very sensitive conscientiousness, arising from the dread of neglect or trespass in the discharge of religious observance, in the trust committed by family or State to its constituted representative. And this trust included also the discharge of duties to other men, the neglect of which might bring down the anger of the Unknown, and even compel the surrender of a criminal as _sacer_ to an offended deity. We find abundant evidence of this aspect of the _religio_ in the language of solemn oaths and treaties, and especially in connexion with the cult of the great Jupiter.