Completion requirements
Visualizing argument structure can help determine how directly or indirectly supporting evidence leads to a conclusion. This section gives examples of simple and more complex arguments using arrows to represent the structure of an argument. Complete the exercises and then check your answers. The answer key has the arguments in standard form, but there is no key for the diagramming.
Exercise
Write the following arguments in standard form and show how the argument is structured using a diagram like the ones I have used in this section.
- There is nothing wrong with prostitution because there is nothing
wrong with consensual sexual and economic interactions between
adults. Moreover, since there's no difference between a man who
goes on a blind date with a woman, buys her dinner and then has sex
with her and a man who simply pays a woman for sex, that is another
reason for why there is nothing wrong with prostitution.
- Prostitution is wrong because it involves women who have typically
been sexually abused as children. We know that most of these
women have been abused from multiple surveys done with women
who have worked in prostitution and that show a high percentage of
self-reported sexual abuse as children.
- There was someone in this cabin recently because there was warm
water in the tea kettle and because there was wood still smoldering in
the fireplace. But the person couldn't have been Tim because Tim has
been with me the whole time. Therefore, there must be someone else
in these woods.
- It is possible to be blind and yet run in the Olympic Games since
Marla Runyan did it at the 2000 Sydney Olympics.
- The train was late because it had to take a longer, alternate route
since the bridge was out.
- Israel is not safe if Iran gets nuclear missiles since Iran has threatened
multiple times to destroy Israel and if Iran had nuclear missiles it would
be able to carry out this threat. Moreover, since Iran has been
developing enriched uranium, they have the key component needed
for nuclear weapons - every other part of the process of building a
nuclear weapon is simple compared to that. Therefore, Israel is not
safe.
- Since all professional hockey players are missing front teeth and
Martin is a professional hockey player, it follows that Martin is missing
front teeth. And since almost all professional athletes who are missing
their front teeth have false teeth, it follows that Martin probably has
false teeth.
- Anyone who eats the crab rangoon at China Food restaurant will
probably have stomach troubles afterward. It has happened to me
every time, which is why it will probably happen to other people as
well. Since Bob ate the crab rangoon at China Food restaurant, he will
probably have stomach troubles afterward.
- Albert and Caroline like to go for runs in the afternoon in Hyde Park.
Since Albert never runs alone, we know that any time Albert is
running, Caroline is running too. But since Albert looks like he has just
run (since he is panting hard), it follows that Caroline must have ran
too.
- Just because Jeremy's prints were on the gun that killed Tim and the
gun was registered to Jeremy, it doesn't follow that Jeremy killed Tim
since Jeremy's prints would certainly be on his own gun and someone
else could have stolen Jeremy's gun and used it to kill Tim.