 Now, one line of response might be to say that the doubts the skeptic raises over our modal knowledge here can themselves be blocked or shown to be spurious, for example, by providing evidence for the reliability of our methods in the modal case, or questioning the right of the skeptic to use the mere possibility of error against such knowledge. But then, it seems likely that similar claims could also be used to bolster the credentials of our non-transcendental bases for knowledge, such as perception and memory, in a way that would then render the transcendental argument redundant.