Recipe

Identify the form of an everyday argument

Use when: an everyday passage argues for something and you want to know whether its pattern is one of the named valid forms or a look-alike

Goal: the argument's skeleton in letters, matched to a named form or fallacy (or marked as matching none)

Taught in Recognizing forms in the wild

1. 1

   Decide which claim the passage is trying to establish. Look for so, therefore, which means, or a claim the others are offered to support. It may come first.

   Example

   "You'll be charged a late fee, since the bill was due Friday and you paid Monday." The conclusion is "you'll be charged a late fee."

   Why: every named form is defined by how the premises lead to the conclusion, so you can't match anything until you know which line is the conclusion.

2. 2

   Write down every reason given. If the step from reasons to conclusion needs an unstated link, add the most reasonable one.

   Example

   Stated: "the bill was due Friday and you paid Monday." Missing: "if you pay after the due date, you're charged a late fee."

   Why: the form belongs to the full argument; judging it with a premise missing tests a shape the speaker never meant.

3. 3

   Turn reversed "if" clauses, "whenever," "provided that," and "unless" into "if … then"; turn "but" into "and."

   Example

   "We'll hike unless it's icy" becomes "if it's not icy, we'll hike."

   • the passage says "unless" — rewrite as "if not-Q, then P," and don't add the reverse unless the passage states it.
   • the passage flips an "if" clause to the end — move it to the front before labeling.

   Why: the named forms are stated with "if … then," "or," "and," and "not," so the passage has to be in those words before it can match.

4. 4

   Give each distinct claim a letter, the same letter every time it recurs, and pull every "not" outside its letter.

   Why: the letters are what make two different passages comparable; one claim under two letters, or two claims under one, hides the real pattern.

5. 5

   Compare with the catalog. For an "if" argument, check what the second premise does to which part. For an "or" argument, check whether an option is denied or asserted. For a dilemma, check what the "or" premise does.

   • it matches a valid form — the argument is valid.
   • it matches a look-alike — the form is invalid; give a counterexample to confirm it.
   • it matches nothing named — fall back on the counterexample test; no match is not a verdict.

   Why: each valid form and its look-alike differ at exactly one position, so that position decides the match.