Again, it is to be borne in mind that there may be real union without unity in creed. As Churches may be truly one though, for the sake of convenience or of some conscientious scruple, they maintain a separate existence, so the unity required in the New Testament is not uniformity of belief in respect to all articles of faith. This uniformity is desirable; it is desirable that all men know the truth. Paul here and elsewhere entreats his readers to endeavour to agree and be of one mind. It is quite true that the Church has gained much by difference of opinion. It is true that were all men to be agreed there might be a danger of truth becoming lifeless and forgotten for want of the stimulus it derives from assault, and discussion, and cross-questioning. It is undoubtedly the fact that doctrine has been ascertained and developed precisely in proportion and in answer to the errors and mistakes of heretics; and were all assault and opposition even now to cease, there might be some danger of a lifeless treatment of truth ensuing. And yet no one can desire that men be in error; no one can wish heresies to multiply that the Church may be stimulated. A visitation of cholera may result in cleanliness and carefulness, but no one desires that cholera may come. Opposition in Parliament is an acknowledged service to the country, yet each party desires that its sentiments become universal. So, too, notwithstanding every good result which may flow from diversity of opinion regarding Divine truth, agreement and unanimity are what all should aim at. We may even see reason to believe that men will never all think alike; we may think that it is not in the nature of things that men of diverse natural disposition, diverse experience and upbringing, should think the same thing; if it is true, as a great thinker has said, that "our system of thought is very often only the history of our heart," then the effort to bring men to precise uniformity of thought is hopeless: and yet this effort must be made. No man who believes he has found the truth can forbear disseminating it to the utmost of his ability. If his favourite views are opposed in conversation, he does what he can to convince and make converts of his antagonists. There is truth, there is a right and a wrong, and it is not all the same whether we know the truth or are in error; and doctrine is simply truth expressed: and though the whole truth may not be expressed, yet even this partial expression of it may be much safer and nearer what we ought to believe than some current denial of the truth. Paul wishes people to believe certain things, not as if then they would be fully enlightened, but because so far they will be enlightened and so far defended against error. But the question remains, What truths are to be made terms of communion? Is schism or secession ever justifiable on the ground that error is taught in the Church?