Steadily, with caution and a sober spirit, he had employed his energies and vast accumulated stores of knowledge in piling up breakwaters against their pernicious innovations.

In all his controversial writings during the interdict Sarpi used none but solid arguments, drawn from Scripture, canon law, and the Councils of the early Church, in order to deduce one single principle: namely that both secular and ecclesiastical organisms, the State and the Church, are divinely appointed, but with several jurisdictions and for diverse ends.
He pressed this principle home with hammer-strokes of most convincing proof on common sense and reason.

He did so even superfluously to our modern intellect, which is fatigued by following so elaborate a chain of precedents up to a foregone conclusion.

But he let no word fall, except by way of passing irony, which could bring contempt upon existing ecclesiastical potentates; and he maintained a dispassionate temper, while dealing with topics which at that epoch inflamed the fiercest party strife.

His antagonists, not having sound learning, reason, and the Scripture on their side, were driven to employ the rhetoric of personal abuse and the stiletto.