Fallacy of Four Terms/Examples/Arbitrary Example 1

Examples of Fallacy of Four Terms

The following is an example of the fallacy of four terms:

$(1): \quad$ All metals are elements.

$(2): \quad$ Brass is a metal.

$(3): \quad$ Therefore, brass is an element.

It is common to refer to an alloy as an example of a metal.

That is how the word metal is used in $(2)$.

However, when used in $(1)$, the word metal is being used in its exclusive sense, that is, metals which are elements.

Hence there are $4$ terms in the syllogism:

metal, in the true sense

Brass

metal, in the sense which includes alloys.

$\blacksquare$