Subsection 1.4.1 Introduction
Logic is the study of valid argument (proof) structures (i.e., arguments that preserve truth).
It lets us construct and understand good arguments.
![Video cover image](images/ch1purposeproof.jpg)
Activity 1.4.1.
In his classic novel, Catch-22, Joseph Heller clearly describes the Army’s rules for getting a mental health discharge. There are two:
To get a discharge, you’ve got to be crazy and you’ve got to request the discharge.
If you request a mental health discharge, you’re clearly not crazy – any sensible person would make exactly such a request.
From these two rules, we can reason logically and conclude that it’s not possible to get a mental health discharge.
Try proving this yourself.