To show that this kind of progress is to be admitted only two things are to be proved: 1: That some divinely revealed truths should be contained in the Apostolic teaching _implicitly, less clearly explained, less urgently pressed_. And this can be denied only by those who hold that the Bible is the only rule of Faith, that it is clear in every part, and could be readily understood by all from the beginning. This point I shall consider farther on in this work. 2. That the Church can, in process of time, as occasions arise, _declare, explain, urge_. This is proved not only from the Scriptures and the Fathers, but even from the conduct of Protestants themselves, who often boast of the care and assiduity with which they “search the Scriptures,” and study out their meaning, even now that so many Commentaries on the sacred Text have been published. And why? To obtain more light; to understand better what is revealed. It would appear from this that the only question which could arise on this point is, not about the possibility of arriving by degrees at a clearer understanding of the true sense of revelation, as circumstances may call for successive developments, but about the authority of the Church to propose and to determine that sense. So that, after all, we are always brought back to the only real point of division and dispute between those who are not Catholics and ourselves, namely, to the authority of the Church, of which I shall have more to say hereafter. I cannot conclude better than by quoting the words of St. Vincent of Lerins: “Let us take care that it be with us in matters of religion, which affect our souls, as it is with material bodies, which, as time goes on, pass through successive phases of growth and development and multiply their years, but yet remain always the same individual bodies as they were in the beginning.... It very properly follows from the nature of things that, with a perfect agreement and consistency between the beginnings and the final results, when we reap the harvest of dogmatic truth which has sprung from the seeds of doctrine sown in the spring-time of the Church’s existence, we should find no substantial difference between the grain which was first planted and that which we now gather. For though the germs of the early faith have in some respects been evolved in the course of time, and still receive nourishment and culture, yet nothing in them that is substantial can ever suffer change. The Church of Christ is a faithful and ever watchful guardian of the dogmas which have been committed to her charge. In this sacred deposit she changes nothing, she takes nothing from it, she adds nothing to it.” Chapter III. THE HOLINESS OF THE CHURCH. Holiness is also a mark of the true Church; for in the Creed we say, “I believe in the _holy_ Catholic Church.”