Synderesis their opposites as evils to be avoided. Synderesis is the capacity not only to apprehend the first principles, but also to judge every step of the practical discourse in the light of those principles. But, as an intellectual disposition concerned with knowledge of the first principles of action, synderesis provides only the universal premise of the practical syllogism. Every human "action", however, is singular, contingent and takes place in particular circumstances. To complete the practical discourse and reach a conclusion regarding what has to be done "hic et nunc" [here and now] and what means are to be used, other
Quanta cura if he trampled on the consciences of his subjects,—if he had done so all along, as Protestants say, then he could not have lasted all these many centuries till now, so as to supply a mark for their reprobation. [...] I wish to answer this important objection distinctly. 2. Secondly, I observe that conscience is not a judgment upon any speculative truth, any abstract doctrine, but bears immediately on conduct, on something to be done or not done. "Conscience," says St. Thomas, "is the practical judgment or dictate of reason, by which we judge what hic et nunc is to