But why do we value consistency? In science and in our everyday beliefs about the way things are, there is a straightforward answer. Inconsistent beliefs, taken together, form a contradiction: a proposition that has the form “p and not p.” We assume that reality does not contain contradictions (an assumption first articulated by Parmenides). So we infer that an inconsistent set of beliefs cannot possibly be an accurate description of the way things are.
…To sum up: I’m not saying that we should stop caring at all about logical consistency in working out our positions on moral issues. But I think it is interesting and reasonable to ask why we do care. Moral philosophers, as theoreticians, naturally tend to focus on the theoretical coherence of statements and their implications. But morality isn’t mathematics. It is perfectly rational, in one sense of the term, to prioritize practical consequences over logical consistency. Once we accept this, we will perhaps be more comfortable taking a pragmatic approach to moral problems, and feel free to do so without dissimulation or apology.
With Isaiah Berlin’s concept of value pluralism never far from my thoughts, I was already receptive to this argument. To me, those two lines are key: “We assume that reality does not contain contradictions,” and “morality isn’t mathematics.” Axioms themselves are often unexamined. At any rate, it’s an excellent essay, well worth a careful reading.
February 17, 2014 @ 4:40 pm
Pedantic note: "Consistency" also refers to maintaining the same position through time, so I learned to use the word "coherence" for "lacking contradictions".
The problem with abandoning respect for either, to any degree, is that one would no longer have grounds for criticising any position. The reasponse would simply be, "You choose your way of being incoherent and inconsistent, and I'll choose mine."
February 18, 2014 @ 12:04 am
"Epistemological relativism may be true for you, but it isn't true for everyone."