ABSTRACT
Several senses of consistency and completeness can be distinguished, so the main questions give rise to more special questions whether the system is consistent in this or that sense. Consistency with respect to negation is inapplicable unless the system contains an identifiable negation-operator; and consistency in the sense of Post is applicable only if the system contains some class of variables identifiable as propositional variables. The root of the notion of completeness is to be found in that of the adequacy of an axiomatic system as an axiomatization of some field, in the sense that the axiomatic basis is sufficiently powerful to generate all the truths of that field. If a system is complete in the sense just explained, this means that the axiomatic basis is sufficient for the generation of the set of all its valid well-formed formula.
