Very early, owing in part to English Protestant propagandists, the word Jesuitical came to characterize a form of argument designed less to seek the truth than to make a case, a form of argument that was aggressive and clever but perhaps not always sincere--indeed, one that was at times cunningly equivocal or downright deceitful.
Jesuitical was believed to be a sincere form of argument, that was also slightly mentally deficient.