Home / Tutorial 4

Previous | Up | Next

4.9 Support versus Co-premise II

A similar mistake - the flip side of the previous one - is mapping a co-premise as if it were a supporting reason.


The American flag is seen moving in video footage recorded when the astronauts planted it on the lunar surface. Given that there is no atmosphere on the Moon, some see this as 'proof' that the scenes were filmed on earth. [6.1]

The reasoning in this passage appears to contain two simple arguments.  In fact, however, the passage gives two co-premises of a single simple argument.


There is no atmosphere on the Moon is not really evidence for The American flag is seen moving...

In fact it is a co-premise in the first argument.  Note that other co-premises have not yet been articulated.

 Glossary | Contents

Previous | Up | Next

Copyright Critical Thinking Skills BV -