Will presented Roger White’s paper “Epistemic Permissiveness” (White 2005). This paper argued for the truth of the Uniqueness thesis. This holds that a given body of evidence can justify only one attitude towards a proposition, where an attitude could be belief, denial, or a degree of confidence. White calls those who deny the Uniqueness Thesis “permissivists” and this paper is devoted to arguing against permissivism. The idea is to argue for the Uniqueness Thesis by refuting attempts to deny it.
If he’s right, then, it seems, there cannot be such a thing as reasonable disagreement. That would be a very dramatic conclusion, since most of us believe that it is possible for people to reasonably disagree about at least some things. In particular, social life would be quite unpleasant if we did not at least act as though reasonable disagreement was possible.
In a nutshell, the objection to permissivism goes like this. Suppose that one body of evidence could justify one of two different beliefs. Then what would lead a person to have one of those beliefs would have to be something other than the evidence. But it is irrational to believe something without evidence. Therefore, permissivism must be wrong.
We talked about how the examples White uses work and how they might have been altered in various ways. We also talked about the importance of identifying the core part of a piece of philosophical writing: the 3-5 pages or so where the main argument is laid out as opposed to the set-up, conclusion, more complicated restatements, or answers to objections. Studying the core argument intently almost always pays great dividends. Among other things, you can usually skim or even ignore the rest. But you have to find it. One method of doing that is to skip to the end. That’s where the author will usually say what was most important. Ideally, the author will identify it at the beginning as well, but sometimes authors think their readers want a sense of surprise.
We ended with Peter and Octave each identifying a possible limitation to the way the problem has been set up. Peter suggested that it might be that most of what we call reasonable disagreement really stems from different people having different evidence. If so, what we call reasonable disagreement could be compatible with the truth of the Uniqueness thesis because it would not involve making an irrational move from one body of evidence to two or more different conclusions. Octave noted that we had not spent much time on what “evidence” means and suggested that the problem might seem less dire if we spelled it out.
Both points are good ones and led naturally to another reading on Will’s list. Huzzah!
White, Roger. 2005. “Epistemic Permissiveness.” Philosophical Perspectives, no. 19: 445–59. doi:10.1111/j.1520-8583.2005.00069.x.