Checking Argument Terms

Use this checklist to evaluate an argument:

• Identify the three terms — major (predicate of the conclusion), minor (subject of the conclusion), middle (the bridge).
• Check the middle term — does it appear in both premises with the exact same meaning?
• Look for equivocation — is any word being used in two different senses?
• Test distribution — does the middle term cover all members of a category in at least one premise?

Write the argument out with the terms labeled. If the middle term shifts meaning, the argument is invalid no matter how convincing it sounds.