Further on the criteria of truth and error

[T]he history of thought […] reveal[s] discrepancy between the intuitions of one age and those of a subsequent generation. But where the conflicting beliefs are not contemporaneous, it is usually not clear that the earlier thinker would have maintained his conviction if confronted by the arguments of the later. The history of thought, however, I need hardly say, affords abundant instances of similar conflict among contemporaries; and as conversions are extremely rare in philosophical controversy, I suppose the conflict in most cases affects intuitions—what is self-evident to one mind is not so to another. It is obvious that in any such conflict there must be error on one side or the other, or on both. The natural man will often decide unhesitatingly that the error is on the other side. But it is manifest that a philosophic mind cannot do this, unless it can prove independently that the conflicting intuitor has an inferior faculty of envisaging truth in general or this kind of truth; one who cannot do this must reasonably submit to a loss of confidence in any intuition of his own that thus is found to conflict with another’s.