Self-study
Marion knows that the bridge on her usual route is closed and that, Support unless she takes the train instead of driving, she can get to work on time only by leaving at least 45 minutes early. ███ ████ ██ ██ ███ ████████████ ████ ██████ ███████ ███ █████ ████████ ███ ███ ████ ████ ███ ██ ████ ██ ████ ███ ███ ██ ██ ██ ██ ███ ██████ ██ ███████ ██████ ██████████ █████ ███ █████ ██████ ███ ██████ ██████ ██████ █████ █████ ████ ███ █████
Summarize Argument
The author concludes that Marion can’t avoid being late for work. He supports this with four premises:
(1) Marion hates taking the train.
(2) If she doesn’t take the train, she must leave 45 minutes early to be on time for work.
(3) If she leaves 45 minutes early, her bank won’t be open yet.
(4) She must stop at her bank before leaving for work (so she can’t leave 45 minutes early).
Identify and Describe Flaw
The author never establishes that Marion will drive to work. Instead, he assumes that Marion won't take the train simply because she hates it, without providing any other evidence. Marion could still take the train, even if she dislikes it, and she might then have enough time to visit the bank and be on time for work.
26.
The reasoning in the argument ██ ██████ ███████ ███ ████████
a
mistakes a situation ████ ██████ █████████ ███████ ████ ██████ ███ ███ ████ ███████ █ ██████████ ██████ █████
The bridge closure may affect many people, but the author’s conclusion is based on premises about Marion’s schedule and needs. He’s not mistaking a situation that affects many people for one that affects Marion alone because he’s only addressing Marion’s particular situation.
b
ignores the fact ████ ██████ █████ ████ ████ █████████ ██ ███ ████ ███████ ███████████ ███ ███ ████████████ ████ ██████ ████ ███ █████ ███ ████
This doesn’t point out the assumption that, just because Marion hates the train, she won’t take the train. Also, the argument is only about whether Marion will be late for work; the author doesn’t need to consider all the consequences of her being late.
c
assumes without justification ████ ███████ ██████ █████████ ████ ██ ████████ ██ ████████ █ █████ ███████ ███ ██████████ ██████ ████ ████ ██ ████████ ██ ████████ ████ ██████
This is the cookie-cutter “whole-to-part” flaw. But like (A), the author’s conclusion is based on premises about Marion’s schedule and needs, not on premises about people in general.
d
treats evidence that ███████ ████ █████ █ ██████████ ██████ ██ ██████ ██ ██████ ████ ████████ ████████ ███ ███████████ ██ ██ ███████████ ██████ ██ ██████
Marion hates the train. The author takes this evidence to mean that she won’t take the train and will drive instead. He mistakenly uses this to exclude the alternative possibility that she might still take the train, despite hating it.
e
overlooks the possibility ████ ███████ █████ ████████████ █████ █ █████ ██████ ██ ██████ ███████ ██████ █ ████ ██████ ███ █████ ██
The author isn’t assuming that Marion won’t take the train because she doesn’t have a good reason for doing it. Instead, he’s assuming that Marion won’t take the train because she hates taking the train.