Philosophy Talk: "Bayesianism and the Evidence Problem"
Lisa Cassell, University of Massachusetts/Amherst
Location
Performing Arts & Humanities Building : 456
Date & Time
February 15, 2017, 4:00 pm – 6:00 pm
Description
Lisa Cassell, University of Massachusetts/Amherst, "Bayesianism and the Evidence Problem":
Bayesianism is a theory that gives us norms for how
the degrees of belief we have in certain propositions---our "credences"---ought
to hang together. For instance, it tells me that if my credence that I
will play baseball tomorrow is .3 and my credence that I will play basketball
tomorrow is .4, then, if I believe that I will only play one or the other, my
credence that I will either play baseball tomorrow or basketball tomorrow is
.7. One of Bayesianism’s most attractive features is its updating norm,
which gives us a simple and powerful way of revising our beliefs in the light
of new evidence. However, Bayesians have an “Evidence Problem”: while
their updating norm tells us what to do once we get evidence, it doesn’t tell
us what it means to actually have evidence. In this
talk, I consider two arguments---one in support of Bayesian’s updating norm and
one against it—and show that both of these arguments fail. I go on to
consider what these failures teach us about the Evidence Problem. I
conclude by considering some different ways of resolving this problem.