Mr. Garrison says vehemence is necessary.

A Reason
In attacking the system of slavery, why so vehement? so unyielding? so severe ? Because the times demand vehemence. An immense iceberg, larger and more impenetrable than any which floats in the arctic ocean, is to be dissolved, and a little extra heat is not only pardonable, but absolutely necessary. Because truth can never be sacrificed, and justice is eternal. Because great crimes and destructive evils ought not to be palliated, nor great sinners applauded. With reasonable men, I will reason; with humane men I will plead; but to tyrants I will give no quarter, nor waste argument where they will certainly be lost.

(Liberator, January 14, 1831, pg 3)