  \((M)\) claims that whatever is necessary is the case. Notice that \((M)\) would be incorrect were \(\Box\) to be read ‘it ought to be that’, or ‘it was the case that’. So the presence of axiom \((M)\) distinguishes logics for necessity from other logics in the modal family. A basic modal logic \(M\) results from adding \((M)\) to \(\bK\). (Some authors call this system \(\mathbf{T}\).)