Final answer:
It is false that abolitionists and proslavery writers disagreed over the irreconcilability of the North-South conflict over slavery; in fact, both sides agreed it was irreconcilable. While not all viewed this as an immediate precursor to war, the concept of an irrepressible conflict was recognized.
Step-by-step explanation:
Abolitionists and proslavery writers disagreed on many aspects regarding the institution of slavery, including the idea that the conflict between the North and the South was irreconcilable.
The statement in question is false, as Abolitionists and proslavery writers actually agreed that the conflict between the North and the South over slavery was irreconcilable.
While both sides held vastly differing views on slavery and had varying degrees of moral concern over the institution, they both recognized that their views were fundamentally opposed and could lead to an irrepressible conflict, as termed by William H. Seward in 1858.
The North feared a 'slave power conspiracy' in politics, while Southerners feared abolitionists' influence, regarding them as a serious threat to the continuation of their way of life.
Even though there were few extremists on either side, the spokesmen felt the need to defend their positions strongly, and as tensions mounted, they saw their conflict over slavery as potentially unresolvable, although not necessarily leading to war initially.