Changes introduced from without.--The Roman religion had, properly speaking, no development. What it might have become had it been left to unfold itself without interference from without, we can only guess; but it was early brought under the influence of more highly developed religions, and it proved to have so little power of resisting innovations that it speedily parted with much of its own native character. The Romans were not unconscious that their religion was an imperfect one; they never claimed, when they were conquering the world, that their religion was the only true one, or had any mission to prevail over others. They were tolerant from the first of the religions of other peoples. The gods of other peoples they always believed to be real beings, with whom it was well for them also to be on good terms. If everything in the world had its spirit, these gods also were the spirits of their own countries and nations; the very notion of deity which the Romans entertained prevented them from having any exclusive belief in their own gods or from denying the right of the gods of others.[2] When therefore they came in contact with foreign religions, they were not protected by any profound conviction of the truth of their own, and were exposed to the full force of the new ideas. The new religions came to them along with the culture of peoples much further advanced in art and in thought than they were themselves; at each such contact, therefore, they felt the foreigner to be superior to themselves in intellectual matters; and wherever this happens, the less highly gifted race is likely to change in its religion as well as in other things. We have to note the changes which were produced by such external influences. [Footnote 2: Cf. Celsus in Origen, _Contra Celsum_, vii. 68.]