 Such an operator may be applied to any formula Φ to produce a term. Among such formulae are the hazardous ones x = x and x ∉ x. The formalizing foundationalist will therefore be careful to adopt a free logic in which it is not assumed, of every well-formed term, that it enjoys a denotation. The proof of Russell’s Paradox can then be deprived of its sting: it simply becomes a proof of the negative existential ¬∃x x = {y | y ∉ y}. 