Syntactic ambiguity

An ambiguous wording in a statement that can lead to misconceptions (and subsequently to false conclusions).

For example, consider the following syllogism Open this example in Syllogism Finder app:

Cars pollute the air.
All electric cars are cars.
From this follows: Electric cars pollute the air.

Although each premise appears to be true and on first glance, this appears to be a formally correct Modus Barbara Show in Syllogism-Finder App, the conclusion is obviously false. The problem lies in the ambiguous wording of the major (first) premise. More information about this in the description below.

• Fallacy of amphiboly
• Structural ambiguity

If a statement is formulated in a way that it can be interpreted in multiple ways, this can lead to misconceptions about the validity of the statement.

In the example above, the major clause is an amphiboly of the form of a generic generalization, which can be interpreted both distributively (i.e. as a universal statement, in the sense of “all cars pollute the air”), as well as collectively (i.e. as an existential statement, as if stated in the form: “some cars pollute the air”).

If we assume the latter (“some cars pollute the air”), the premise would clearly be true, but the syllogism is then invalid, as the middle term is not distributed from an existential statement (undistributed middle term). In the former case (“all cars pollute the air”), the form is correct, but the premise is then clearly false - since “all cars” would also include electric cars, which at least do not directly emit pollutants – and from a false premise we can’t get a true conclusion.

This fallacy is also known as the “fallacy of amphiboly”. An amphiboly is an ambiguity in the grammatical structure, which in this case leads to a fallacy of ambiguity.

Although amphibolies are also forms of equivokations, the latter term is broader and includes, above all, polysemies, i.e. words and expressions that have multiple extensions. The fallacies that result from such equivocations are described under “Four-Term Fallacy” and in related articles.

• Equivokation
  • Amphiboly
• Generic generalization

• Syntactic ambiguity on Wikipedia