Tutorial Two

The following passage provides an "argument", that is, it contains reasoning or evidence for a conclusion.

Sara and Beth are students in Logic 101 and are identical twins. Like many such twins, Sara and Beth share more than just physical traits: they tend to behave in similar ways, share interests down to very specific details, and are emotionally very similar. So, one can conclude with some confidence that Sara will love logic just in case Beth does.

Notice that this argument is not particularly combative. The word "argument" is commonly used to include any kind of statement of reasoning, not just disputation.

We will use the word in this non-combative way.

Definition: An argument is a collection of statements some of which (the premises) are given as reasons for another member of the collection (the conclusion).

Statements are sentences which have a "truth value", that is, they are either true or false.

There are many ways in which we can express our reasoning in natural language. Sometimes, as in the above example about the twins, the premises come first followed by the conclusion. And here the conclusion is obvious: it follows the words "so, one can conclude".

Other passages expressing arguments will be harder to interpret.

  • There may be no words like "so one can conclude" to indicate a conclusion.
  • Sometimes premise and conclusion order will be different from the above example.
  • At other times, extraneous claims will be made which are not parts of the argument.
  • And frequently no argument at all will be made in a passage.

So, we'll need to work on identifying argument structure within a passage.

To begin, read the following passage and click on its conclusion.

Chris will likely be admitted to law school because he has done well at college and scored well on the LSATs.

(Note that this one sentence passage in the box is made up of several component statements. Each of these is in blue. Click on the one expressing the passage's conclusion.)