I am getting ready to teach logic again. It’s been a while, because I grew discontent
with the standard curriculum. Maybe PEA Soupers
can help me out. What are we trying to
achieve in a logic class?
1. We are
trying to make students better reasoners.
If this is the goal, I wonder if there is any empirical evidence that
our standard methods, using Ps and Qs and symbols, work. The one piece of evidence I know of, the
Wason Selection Test, indicates that they don’t . Moreover, I suspect that most errors of
reasoning are not cognitive at root, but emotional—people get invested in
conclusions and will use any argument to defend them, overlook counterevidence,
evaluate their own side more charitably, etc.
(There is empirical evidence for this too.) Logic curricula never address this issue.
2. 2. We are giving students tools to analyze
arguments and evaluate them better. This
is what I use logic for. Sometimes in
philosophy I am faced with a tricky argument which formalization clarifies as nothing
else can. However, usually if I need to
do this, I have to use more than undergraduate logic: I need second-order quantification, or
possible worlds, or
counterfactuals. Maybe undergraduates
still profit, however, because I’m good enough at undergraduate-level logic
that I don’t need formalization for anything at that level, while they
would. Another problem, however, is that
most arguments outside philosophy—in op-ed pages or magazines, for example—aren’t
even remotely formal, and formal tools don’t help you evaluate them at
all. That indicates that logical
training, as it is currently pursued, is mostly useful within philosophy…which
is not how it is usually advertised, at any rate.
3. 3. We are teaching students to expose the logical
structure of our language. If this is
the goal, we are doing a lot of lying.
Nobody with an acquaintance with quantifier theory now believes that “All
Fs are Gs” is, in its logical structure, an unrestricted universal quantification
over a material implication. Likewise
for “Some Fs are Gs.” And as best I can
tell, no more than half of informed people would say that “If” is a
All of this indicates to me that the logic curriculum needs
a big re-think. However, I am not sure
what would be good reforms. Covering causal,
probabilistic and statistical reasoning and fallacies? Covering common psychological errors in
reasoning (fundamental attribution error, confirmation bias, etc.)? Eliminating the way we usually do conditionals
and quantifiers? Modal logic up
front? (Surely not.) And
maybe I am being too pessimistic?