Carrying a doubt for years is a virtue that few possess, and that very few learn to cultivate. And it seems that without it, a true intellectual is not formed. Doubt is an oscillation and also an opening, which is why it differs from certainty, which usually leads to the question being closed. If sustained by a sincere interest, doubt stimulates, and the resulting activity is sometimes more beneficial than finding a possible solution. Dialectical confrontation is the basis of any valuable knowledge; and it seems that, strangely enough, the extension of the former places great value on what can be known.