Assertion and reason: diagrams

Exercise and reference answers

Questions

1. Reason

   They make every arrangement the premises allow visible at once.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   Diagrams are a reliable test for these arguments.

2. Reason

   The premises often permit several, and the conclusion must hold in all.

   Verdict

   Both are true; the reason explains the assertion.

   Assertion

   You must try more than one arrangement.

3. Reason

   Each circle represents a class of things.

   Verdict

   The assertion is false and the reason is true.

   Assertion

   A larger circle means a larger class.

Explanation