Since I sphere, include is a logical conse quence of Huntington's postulates, the above hypothetical statement is a truth of logic; it involves the expressions 'sphere' and 'includes' inessen tially, in fact vacuously, since the logical deducibility of the theorems from the postulates is independent of the meanings of 'sphere' and 'in cludes' and survives the replacement of those expressions by any other grammatically admissible expressions whatever.