If a variable is universally quantified, the formula following it has the same truth value as the formula beginning with the universal quantifier regardless of the move taken.
The universal quantifier for every in this sentence expresses the idea that the claim if "a" is a philosopher, then "a" is a scholar holds for "all" choices of "a".
By introducing dummy variables, any formula in prenex normal form can be converted into a sentence where existential and universal quantifiers alternate.
