— Peter Berger and Anton Zijderveld, In Praise of Doubt (New York: HarperOne, 2009), p. 57.All versions of relativism have one problem in common: How are relativistic thinkers to exempt their own thought from relativistic "deconstruction"? After all, each relativist has a particular location in space and time, which location, if that individual's approach is correct, must determine his or her thought as much as anyone else's. Put differently, the relativist's thought is but one "narrative" among many others that are just as valid.
This puts me in mind of a conversation I once had with a humanities professor who was just flummoxed that any philosophy instructor would try to abstract the views of great philosophers away from their historical context and assess them simply on the basis of their logical worth and evidential support. According to her, there was no way to examine a thesis on its own merits: once one understood the social and economic forces that led to a thesis being posed by someone, there was nothing left to say about it. I'm not very confrontational, especially with probable lost causes, so I did not ask her whether there was actual reason to believe the thesis she just presented, or whether, once one understood the social and economic forces that led her to pose it, there was nothing left to say about it.
It also puts me in mind of my very first philosophy of science professor talking to my class about one of his own encounters with a social constructivist. Social constructivism comes in many forms, but one common form contends (i) that scientific "facts" are merely whatever scientists happen to agree on, and (ii) that what scientists happen to agree on has nothing to do with evidence and everything to do with social forces in the scientific community. Needless to say, social constructivists tend to be sociologists. My professor related his wide-eyed response: "Do you mean to tell me that there are no objective facts about physics, or about chemistry, or about biology, but that there are objective facts about sociology?"