Toproveanargumentisnotvalid,wejustneedtofindacounterexample. ValidArguments? Ifpthenq. q p Ifpthenq. ~p ~q Ifyouareafish,thenyoudrinkwater. Youdrinkwater. Youareafish. Ifyouareafish,thenyoudrinkwater. Youarenota
Thus the grounding of disjunctions has to satisfy the following restricted Internality principle: (∨-Internality) p, q < p ∨ q → ( p ∧ q ∧ p ∨ q → p, q < p ∨ q) However, a straightforward variation of the counterexample to Internality given in Litland (2015, pp. 489–...