True progress, which has forced back or overthrown barbarous practices and institutions that were the source of infinite suffering for men and women,… - Mario Vargas Llosa

The only way to progress is by stumbling, falling, and getting up, time and again. Error will always be there because the best decisions are always, to some extent, bound up in error. In the great challenge of separating truth from lies—a goal, perhaps the most human of all goals, that is perfectly possible to achieve—it is essential to bear in mind that in this task there can never be definitive achievements that cannot be challenged later, and no knowledge that cannot be revised. In the great forest of misperceptions and deceptions, mistakes and mirages, through which we roam, the only way that truth can clear a path is by rational and systematic criticism of what is—or passes for—knowledge. Without this privileged expression of freedom, the right to criticize, we are condemned to oppression, brutality, and also obscurantism.

Do the rhetorical quarrels of bourgeois political parties have anything to do with the interests of the humble and downtrodden?

[T]here is literally no bastion of knowledge, not even in the exact sciences, that ideology, with its powers of distortion, cannot breach and into which lies useful to the cause cannot be implanted.