In a post today, Dave Armstrong claims: "And Protestants continue to argue that folks can disagree on the “secondary” issues and still have unity. Nuh-uh. That ain’t a biblical view. The original Protestants didn’t argue this way at all. They felt that they had spiritual and theological truth and fought for it. It’s only when liberalism came in and continuing Protestant sectarianism, that this other worldview of acceptance of the necessary presence of contradiction and error somewhere, started being accepted." (source)
I'm not going to sit here and correct his grammar or logic. I am simply going to demonstrate from Calvin (one of the Reformers - and someone indisputably entitled to be one of "the original Protestants" by any typical Roman Catholic Standard - which normally places the start of the Reformation with Luther) that - in fact - the Reformers did believe in liberty in the non-essentials (See as well this earlier post):
Calvin, John - Institutes of the Christian Religion (presented here in Beveridge's 1599 translation), Book IV, Chapter 1, Section 12.
Heeding the marks guards against capricious separation
When we say that the pure ministry of the word and pure celebration of the sacraments is a fit pledge and earnest, so that we may safely recognise a church in every society in which both exists our meaning is that we are never to discard it so-long as these remain, though it may otherwise teem with numerous faults.
Nay, even in the administration of word and Sacraments defects may creep in which ought not to alienate us from its communion. For all the heads of true doctrine are not in the same position. Some are so necessary to be known, that all must hold them to be fixed and undoubted as the proper essentials of religion: for instance, that God is one, that Christ is God, and the Son of God, that our salvation depends on the mercy of God, and the like. Others, again, which are the subject of controversy among the churches, do not destroy the unity of the faith ; for why should it be regarded as a ground of dissension between churches, if one, without any spirit of contention or perverseness in dogmatising, hold that the soul on quitting the body flies to heaven, and another, without venturing to speak positively as to the abode, holds it for certain that it lives with the Lord? The words of the apostle are, "Let us therefore, as many as be perfect, be thus minded: and if in any thing ye be otherwise minded, God shall reveal even this unto you," (Phil. 3: 15.) Does he not sufficiently intimate that a difference of opinion as to these matters which are not absolutely necessary, ought not to be a ground of dissension among Christians? The best thing, indeed, is to be perfectly agreed, but seeing there is no man who is not involved in some mist of ignorance, we must either have no church at all or pardon delusion in those things of which one may be ignorant, without violating the substance of religion and forfeiting salvation.
Here, however, I have no wish to patronise even the minutest errors, as if I thought it right to foster them by flattery or connivance; what I say is, that we are not on account of every minute difference to abandon a church, provided it retain sound and unimpaired that doctrine in which the safety of piety consists, and keep the use of the sacraments instituted by the Lord. Meanwhile, if we strive to reform what is offensive, we act in the discharge of duty. To this effect are the words of Paul, "If any thing be revealed to another that sitteth by, let the first hold his peace," (1 Cor. 14: 30.) From this it is evident that to each member of the Church, according to his measure of grace, the study of public edification has been assigned, provided it be done decently and in order. In other words, we must neither renounce the communion of the Church, nor, continuing in it, disturb peace and discipline when duly arranged.