If we wish to find some proof that human beings are of their nature persuaded of the first principles of reasoning, we need look no further than the history of scepticism. As we have seen, any scepticism which truly denied the principles of reasoning would destroy the possibility of thought and of reasoning. But there has never been a sceptic really prepared to abandon resoning for the sake of immersing himself in total mental and verbal silence. All sceptics have used reason to propagate their opinion. By this very fact they admit and use the first principles of reasoning without being conscious of what they are doing. Moreover, they do this naturally because the first principles cannot be denied. The very act of denial presupposes and requires them.
[Antonio Rosmini, Certainty, Cleary and Watson, tr., Rosmini House (Durham: 1991) pp. 76-77 (sect. 1144).]