Dort was not a seminar. The Remonstrant controversy divided the Dutch Republic along political as well as theological lines, setting the mercantile regent class and the province of Holland against the House of Orange and the stricter Calvinist clergy. The synod, which included delegates from England, Switzerland and the German Reformed churches, condemned the Remonstrants; their leading political patron, Johan van Oldenbarnevelt, was executed in 1619, and Hugo Grotius, imprisoned in the same affair, escaped in a book chest. Remonstrant ministers were deprived and exiled, and the movement was tolerated again only after 1630.
Within the Reformed tradition the fault line has always been the third point. Four-point Calvinism, which affirms the other four and holds that Christ's death was in some sense for all, has been a persistent minority position since the seventeenth century, when the French theologian Moise Amyraut argued for a hypothetical universalism, and it is common in contemporary evangelicalism. Reformed critics answer that a redemption intended for all but effective for some makes the atonement's success depend on the recipient, which the other four points deny.
The disputes about the first and fifth points are practical rather than logical. Total depravity is compatible with a high view of common grace and of unregenerate virtue, and Reformed writers have often been accused by their own side of conceding too much there. Perseverance is not the popular doctrine of eternal security, which detaches assurance from any continuing evidence of faith; the confessional position holds that perseverance is visible in a persevering life, and that a professed conversion followed by nothing is grounds for doubting the profession rather than for confidence.
Methodism, Pentecostalism and much of the holiness tradition descend from the losing side at Dort, so the two positions between them account for most of Protestantism.