Argument from genus

You support a claim about one kind of thing by pointing to the wider kind it falls under. The argument works by passing down what is said of the wider class to the narrower one: birds have emotions because all animals do. It can be attacked by showing that the property does not belong to the wider class as such — to every member, because it is a member — but only to most of them as it happens.

Example

Birds have emotions because all animals have emotions

Standardised form

Birds (a) have emotions (X) because all animals (b) have emotions (X).

Transformations applied: none — the example is already in canonical form.

Classification

The subjects differ and the predicate is the same, so the argument form is beta (a is X because b is X).

The conclusion is about some of the animals, namely birds (p), and the premise about all animals (u), so the argument substance is pu.

The keyword BELONGS TO THE GENUS OF describes the relationship between subjects a and b. The argument lever can thus be formulated as “Birds (a) belong to the GENUS of animals (b)”.

Not to be confused with

• Argument from totality — The conclusion is one individual member of the collection, not a kind within it. su
• Argument from species — Runs the other way, from the narrower kind up to the wider one. up
• Argument from division — The premise and conclusion are a thing and its components, not a wider kind and a narrower one. A PART OF

Source

Source not yet recorded.

Notes

Apart from beta form arguments with substance pu, those with substance su or sp also fit the scheme, as the scope of the conclusion is smaller than that of the premise. Different from “argument from totality”, which is an appropriate name for any beta form argument with substance su, sp or pu, in the tradition the name “argument from genus” is reserved for arguments with factual predicates (F).