The arguer says that children should not sleep with artificial night-lighting and supports this claim by stating that the activity leads to myopia. Since the argument fits the form a is X, because a is Y, it can be identified as a first-order predicate argument. In this specific case, a is instantiated by ‘children sleeping with artificial night-lighting,’ X is instantiated by ‘should not happen,’ and Y is instantiated by ‘leads to myopia.’
Children sleeping with artificial night-lighting (a) should not happen (X), because children sleeping with artificial night-lighting (a) leads to myopia (Y)
First-order predicate arguments are further differentiated by identifying the types of statement in the conclusion and the premise. In this case, the former is a statement of policy and the latter a statement of fact, which means that we are dealing with a first-order predicate argument supporting a policy with a fact (1 pre PF).
The trivial name of first-order predicate arguments is derived from the characterization of the relationship between the predicates Y and X. In this example, the undesirable consequence of the activity, that it leads to myopia (Y), functions as a reason for advising that it should not happen (X). Traditionally, such an argument is called a ‘pragmatic argument.’
This example of pragmatic argumentation was presented by Martijn Demollin at the VIOT 2018 Conference and is based on research reported in Quinn et al. (1999), Nature Magazine, 399, 113-114.