If our aim is the objective truth, we can have a motivation and a reason for revising our epistemic norms whenever we have reason to think they aren’… - David Detmer

There is an obscurum per obscurius problem as well. In order to know whether or not hiccups are taller than ants we must first know (a) whether or not there is a consensus that hiccups are taller than ants, and (b) if there is, whether or not the communication that produces that consensus was free, open, and undistorted. But isn’t it obvious that it is easier to determine whether or not giraffes are taller than ants than it is to determine either (a) or (b)? Or, to put it another way, wouldn’t any skeptical doubts about our ability to determine even something so obvious as that giraffes are taller than ants also be more than sufficient to wipe out any hope of being able to know about the outcome, and degree of openness, of any process of public communication?

Surely at least some of our logical principles … are far more evident and obvious to us than are any of the empirical generalizations we find in psychology, or in any other of the empirical sciences. Thus, to attempt to explain logic in terms of psychology is to explain the more certain by the less certain. It is, in short, to commit the fallacy of obscurum per obscurius.

In order to judge that something is not working, wouldn’t we have to know what it’s effects really are? … And surely some of our social practices cannot be judged to be “working” except by invoking the goal of objective truth. For example, to know whether or not the criminal justice system is working well, wouldn’t we have to know something about the accuracy of its results?