Argument from similarity

It is possible that the Tories will recover from their bad position because Labour recovered from their bad position in 2019.

The subjects are different and the predicates are the same, so the argument form is beta (a is X because b is X): “The Tories (a) can possibly recover from their bad position (X) because Labour in 2019 (b) recovered from their bad position (X)”.

Both the conclusion and premise are singular statements (s), so the argument substance is ‘ss’: “The Tories can possibly recover from their bad position (s) because Labour in 2019 recovered from their bad position (s)”.

The keyword SIMILARITY describes the relationship between subjects a and b. The argument lever can thus be formulated as “The Tories (a) are SIMILAR to Labour in 2019 (b)”.

Source

The example is adapted from an article in The Guardian.

Other examples

• Nearly everything we had in the past was recyclable, so nearly everything we have in the future may be recyclable.
• Establishing gun control in the present-day U.S. will lead to genocide because establishing gun control in historical Germany led to genocide (adapted from a campaign ad featuring Joe Wurzelbacher that was published on YouTube under the title Joe the Plumber Ad: Gun Control Caused Holocaust).

Notes

The literature often treats the argument from analogy, argument from similarity, argument from comparison, and argument from equality as if they were the same. In the PTA, “argument from analogy” remains a broad, umbrella label (much like “argument from sign” in the Alpha Quadrant). However, its parametric approach to argument categorization allows for a more precise distinction between the other three argument types by using the distinction between statements of fact (F), value (V), and policy (P) that is used to determine the value of argument substance in the Alpha Quadrant. Applying these labels, it turns out that, typically:

• the argument from similarity has an F-claim supported by an F-claim;
• the argument from comparison has a V-claim supported by a V-claim;
• and the argument from equality has a P-claim supported by an F-claim.